Switch to mdbook v0.4.42 (#118)

Problem
=======

v0.4.42 of mdBook changed a lot of things. This updates to v0.4.42 and
tries to make it as easy as possible to upgrade in the future by making
minimal changes to the core css.

Closes #117 

Testing: It should look and interact the same as the live site with the
following exceptions:
- Slight margin tweaks
- Added paragraph padding

.github/workflows/common/set-up-mdbook/action.yaml

@@ -11,7 +11,7 @@ runs:
       uses: jontze/action-mdbook@0765bef0c7c5792f93bf3ed3d487a0ca32c9da33
       with:
         token: ${{ inputs.token }}
-        mdbook-version: "0.4.40" # Use a semver compatible string
+        mdbook-version: "0.4.42" # Use a semver compatible string
         # Optional Plugins have to be enabled
         use-linkcheck: true
         linkcheck-version: "~0.7.7"

README.md

@@ -15,7 +15,7 @@ and [link checker](https://github.com/Michael-F-Bryan/mdbook-linkcheck). The lin
 or external links.
 
 ```bash
-cargo install mdbook
+cargo install mdbook@v0.4.42
 cargo install mdbook-linkcheck
 npm install
 ```

book.toml

@@ -27,10 +27,9 @@ edit-url-template = "https://github.com/frequency-chain/docs/blob/main/{path}"
 preferred-dark-theme = "coal"
 additional-css = [
   "css/tailwind.css",
+  "css/overrides.css",
   "css/side-nav.css",
   "css/button-links.css",
-  "css/header.css",
-  "css/extended.css",
   "css/highlight.css",
   "css/highlight-dark.css",
 ]