[#1958] Use syntax coloring for code blocks in docs (#2099)

Current code blocks do not use the built-in syntax highlighting
feature offered by Markbind/Markdown.

This impedes the readability of the code within the code blocks.

Let's update the code blocks in the documentation to enable
syntax highlighting to further enhance readability of the documentation
and the code.

docs/dg/learningBasics.md

@@ -82,13 +82,13 @@ Here are some small tasks for you to gain some basic knowledge of the code relat
 
  Therefore, the first step you can take is to add the following to `ArgsParser`.
 
- ```
+ ```java
  public static final String[] JSON_PRINT_MODE_FLAGS = new String[]{"--use-json-pretty-printing", "-j"};
  ```
 
  In `getArgumentParser` method, add the following content to make `ArgumentParser` capture the new argument.
 
- ```
+ ```java
  parser.addArgument(JSON_PRINT_MODE_FLAGS)
  .dest(JSON_PRINT_MODE_FLAGS[0])
  .action(Arguments.storeTrue())
@@ -102,7 +102,7 @@ Here are some small tasks for you to gain some basic knowledge of the code relat
 
  1. Add the following content to `CliArguments` to include `isPrettyPrintingUsed` as a new attribute to the class.
 
- ```
+ ```java
  protected boolean isPrettyPrintingUsed;
 
  public boolean isPrettyPrintingUsed() {
@@ -112,13 +112,13 @@ Here are some small tasks for you to gain some basic knowledge of the code relat
 
  2. In the constructor of `ConfigCliArguments`, add `isPrettyPrintingUsed` as a new parameter of the method, and add the following instruction to the method body.
 
- ```
+ ```java
  this.isPrettyPrintingUsed = isPrettyPrintingUsed;
  ```
 
  3. In the `parse` method of `ArgsParser`, add the following instruction to get `isJsonPrettyPrintingUsed` from `ArgmentParser`.
 
- ```
+ ```java
  boolean isJsonPrettyPrintingUsed = results.get(JSON_PRINT_MODE_FLAGS[0]);
  ```
 
@@ -139,13 +139,13 @@ Here are some small tasks for you to gain some basic knowledge of the code relat
 
  2. Add the following content to `FileUtil`.
 
- ```
+ ```java
  private static boolean isPrettyPrintingUsed = false;
  ```
 
  3. In the `writeJsonFile` method, Replace the creation of the `Gson` object with the following instructions.
 
- ```
+ ```java
  GsonBuilder gsonBuilder = new GsonBuilder()
  .registerTypeAdapter(LocalDateTime.class, (JsonSerializer<LocalDateTime>) (date, typeOfSrc, context)
  -> new JsonPrimitive(date.format(DateTimeFormatter.ofPattern(GITHUB_API_DATE_FORMAT))))
@@ -160,15 +160,15 @@ Here are some small tasks for you to gain some basic knowledge of the code relat
 
  4. To notify `FileUtil` of the switch between different printing mode, add the following method to `FileUtil`.
 
- ```
+ ```java
  public static void setPrettyPrintingMode(boolean isPrettyPrintingAdopted) {
  isPrettyPrintingUsed = isPrettyPrintingAdopted;
  }
  ```
 
  5. It is now possible to notify `FileUtil` of the printing mode switch by extracting the argument from the `CliArguments` object in the `main` method of `RepoSense.java` and passing it to the corresponding method in `FileUtil`.
 
- ```
+ ```java
  FileUtil.setPrettyPrintingMode(cliArguments.isPrettyPrintingUsed());
  ```
 
@@ -225,7 +225,7 @@ Here are some small tasks for you to gain some basic knowledge of the code relat
 
  Add this to the catch block of `spawnCloneProcess` and `waitForCloneProcess`, so that the message will be captured in `summary.json`.
 
- ```
+ ```java
  ErrorSummary.getInstance().addErrorMessage(config.getDisplayName(), e.getMessage());
  ```
  </panel>
@@ -358,7 +358,7 @@ Here are some small tasks for you to gain some basic knowledge of the code relat
 
  Add this to `c_summary.scss`.
 
- ```
+ ```css
  .active-text {
  color: mui-color('green');
  }

docs/dg/styleGuides.md

@@ -22,7 +22,7 @@ Our coding standards are mostly based on those at [se-education.org/guides](http
 
 ## Note on Ternary Operators:
 Ternary operators can be used to shorten if-else blocks such as this:
-```
+```java
 LocalDateTime min = ARBITRARY_FIRST_COMMIT_DATE_UTC.withZoneSameInstant(zoneId).toLocalDateTime();
 if (!commitInfos.isEmpty()) {
  min = commitInfos.get(0).getTime();
@@ -31,7 +31,7 @@ return min;
 ```
 
 The result would look something like this:
-```
+```java
 return (commitInfos.isEmpty())
  ? ARBITRARY_FIRST_COMMIT_DATE_UTC.withZoneSameInstant(zoneId).toLocalDateTime()
  : commitInfos.get(0).getTime();
@@ -48,16 +48,16 @@ In addition to what has been mentioned in the [**Java** coding standard (SE-EDU)
  * This is not necessary (although still recommended) for methods with `@Override` annotations if Javadoc is used. However, if the method that is being overriden is part of your code and has Javadoc, all parameters must be described.
 
 Negative Examples:
-```
-Not okay (Only mentions zoneId parameter):
+```java
+// Not okay (Only mentions zoneId parameter):
 /**
  * Returns a {@link LocalDateTime} object adjusted for timezone given by {@code zoneId}.
  */
 public LocalDateTime adjustTimeZone(LocalDateTime sinceDate, ZoneId zoneId) {
  //Code here
 }
 
-Not okay (@param tag used only for zoneId)
+// Not okay (@param tag used only for zoneId)
 /**
  * Returns a {@link LocalDateTime} object by adjusting {@code sinceDate}
  * to the timezone given by {@code zoneId}.
@@ -69,8 +69,8 @@ public LocalDateTime adjustTimeZone(LocalDateTime sinceDate, ZoneId zoneId) {
 }
 ```
 Positive Example #1:
-```
-Okay (No @param tags):
+```java
+// Okay (No @param tags):
 /**
  * Returns a {@link LocalDateTime} object by adjusting {@code sinceDate}
  * to the timezone given by {@code zoneId}.
@@ -80,8 +80,8 @@ public LocalDateTime adjustTimeZone(LocalDateTime sinceDate, ZoneId zoneId) {
 }
 ```
 Positive Example #2:
-```
-Okay (@param tags used for all inputs):
+```java
+// Okay (@param tags used for all inputs):
 /**
  * Returns a {@link LocalDateTime} object by adjusting {@code sinceDate}
  * to the timezone given by {@code zoneId}.
@@ -98,8 +98,8 @@ public LocalDateTime adjustTimeZone(LocalDateTime sinceDate, ZoneId zoneId) {
  * This requirement does not apply to test code.
  * One `@throws` tag per unique exception.
  * The order of exceptions in the `@throws` tag block should match that of the method's `throws` statement.
-```
-Not okay (order of exceptions in tag block and method signature do not match):
+```java
+// Not okay (order of exceptions in tag block and method signature do not match):
 /**
  * Returns a {@link LocalDateTime} object from {@code dateString}.
  *
@@ -111,7 +111,7 @@ public LocalDateTime parseDate(String dateString) throws NullPointerException, P
  // Code here
 }
 
-Should be:
+// Should be:
 /**
  * Returns a {@link LocalDateTime} object from {@code dateString}.
  *

docs/ug/configFiles.md

@@ -190,15 +190,15 @@ Date: Fri Feb 9 19:13:13 2018 +0800
 ```
 `ActualGitHostId` and `ConfiguredAuthorName` are both `Git Author Name` of the same author.<br>
 To find the author name that you are currently using for your current git repository, run the following command within your git repository:
-``` {.no-line-numbers}
+``` shell {.no-line-numbers}
 git config user.name
 ```
 To set the author name to the value you want (e.g., to set it to your GitHub username) for your current git repository, you can use the following command ([more info](https://www.git-tower.com/learn/git/faq/change-author-name-email)):
-``` {.no-line-numbers}
+``` shell {.no-line-numbers}
 git config user.name "YOUR_AUTHOR_NAME”
 ```
 To set the author name to use a default value you want for future git repositories, you can use the following command:
-``` {.no-line-numbers}
+``` shell {.no-line-numbers}
 git config --global user.name "YOUR_AUTHOR_NAME”
 ```
 RepoSense expects the Git Author Name to be the same as author's username on the Git hosting platform (GitHub, GitLab, BitBucket). If an author's `Git Author Name` is different from their username on the Git hosting platform, the `Git Author Name` needs to be specified in the standalone config file. If the author has more than one `Git Author Name`, multiple values can be entered too.