chore(docs): update bootstrap to bootstrap@4

#### Describe the PR current bootstrap version is version 5: https://www.npmjs.com/package/bootstrap
bootstrap-vue · Jan 19, 2023 · ab777a4 · ab777a4
1 parent a8a5d4e
commit ab777a4
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/docs/markdown/intro/README.md b/docs/markdown/intro/README.md
@@ -119,10 +119,10 @@ version of Vue.js, Bootstrap v4 and BootstrapVue:
 
 ```bash
 # With npm
-npm install vue bootstrap bootstrap-vue
+npm install vue bootstrap@4 bootstrap-vue
 
 # With yarn
-yarn add vue bootstrap bootstrap-vue
+yarn add vue bootstrap@4 bootstrap-vue
 ```
 
 Then, register BootstrapVue in your app entry point (typically `app.js` or `main.js`):