bring back old README

HOW_TO_HOST_WEBSITE_LOCALLY.md

@@ -0,0 +1,42 @@
+[PGQL's website](http://pgql-lang.org/) is based on Jekyll and GitHub pages. You can change any of the files and GitHub will automatically build and deploy the changes. Changes are reflected after roughly 30 seconds.
+
+To host the website locally, download Rancher Desktop:
+
+- In the welcome screen choose "dockerd (moby)"
+- Restart your machine
+- To avoid `chown: .jekyll-cache: Permission denied` when running the docker command below, create `~/Library/Application\ Support/rancher-desktop/lima/_config/override.yaml` with contents:
+
+```
+mountType: 9p
+mounts:
+ - location: "~"
+ 9p:
+ securityModel: mapped-xattr
+ cache: "mmap"
+```
+Then restart Rancher Desktop.
+
+Then run:
+
+```
+docker run --rm --volume="$PWD:/srv/jekyll:Z" -it -p 4005:4005 jekyll/jekyll jekyll serve
+```
+
+Once it shows `Generating...` it may seem stuck but you have to be patient (takes ~10 minutes).
+
+Then open [http://localhost:4005/](http://localhost:4005/) in your browser.
+
+Changes to any of the files will automatically be reflected after 30-60 seconds depending on the size of the change.
+
+After changing section titles or grammar snippets, regenerate necessary menus and hyperlinks as follows:
+
+```
+bash generate-menus-and-hyperlinks.sh
+```
+
+Once in a while we should update the dependencies:
+
+```
+export JEKYLL_VERSION=3.8
+docker run --rm --volume="$PWD:/srv/jekyll:Z" -it jekyll/jekyll:$JEKYLL_VERSION bundle update
+```