feat: use mdbook-last-changed to indicate when a file has been last updated

.env

@@ -1,3 +1,4 @@
 MDBOOK_VERSION=0.4.37
 MDBOOK_I18N_HELPERS_VERSION=0.3.2
 MDBOOK_PANDOC_VERSION=0.6.0
+MDBOOK_LAST_CHANGED_VERSION=0.1.4

.github/workflows/install-mdbook/action.yml

@@ -26,10 +26,17 @@ runs:
         echo "version=$MDBOOK_PANDOC_VERSION" >> $GITHUB_OUTPUT
       shell: bash
 
+    - name: Read mdbook-last-changed version from .env
+      id: mdbook-last-changed-version
+      run: |
+        . ./.env
+        echo "version=$MDBOOK_LAST_CHANGED_VERSION" >> $GITHUB_OUTPUT
+      shell: bash
+
     - name: Install dependencies
       uses: taiki-e/install-action@v2
       with:
-        tool: mdbook@${{ steps.mdbook-version.outputs.version }},mdbook-pandoc@${{ steps.mdbook-pandoc-version.outputs.version }},mdbook-i18n-helpers@${{ steps.mdbook-i18n-helpers-version.outputs.version }}
+        tool: mdbook@${{ steps.mdbook-version.outputs.version }},mdbook-pandoc@${{ steps.mdbook-pandoc-version.outputs.version }},mdbook-i18n-helpers@${{ steps.mdbook-i18n-helpers-version.outputs.version }},mdbook-last-changed@${{ steps.mdbook-last-changed-version.outputs.version }}
 
     - name: Install mdbook-pandoc and related dependencies
       run: |

book.toml

@@ -23,7 +23,14 @@ site-url = "/patterns/"
 git-repository-url = "https://github.com/rust-unofficial/patterns"
 git-repository-icon = "fa-github"
 edit-url-template = "https://github.com/rust-unofficial/patterns/edit/main/{path}"
-additional-css = ["theme/css/language-picker.css"]
+additional-css = [
+  "./theme/css/language-picker.css",
+  "./styles/last-changed.css",
+]
+
+[preprocessor.last-changed]
+command = "mdbook-last-changed"
+renderer = ["html"]
 
 [output.html.fold]
 enable = true

styles/last-changed.css

@@ -0,0 +1,7 @@
+footer {
+  font-size: 0.8em;
+  text-align: center;
+  border-top: 1px solid grey;
+  padding: 1.25em 0;
+  margin-top: 1.25em;
+}