New anchor redirections JS before switch to Nginx (#567)

Nginx does not support anchor redirects nor does it support a `.htaccess` file at the root of the website. Only other viable options is to add a JS in every HTML file when site is built to handle them.

See: https://squidfunk.github.io/mkdocs-material/customization/?h=javascript#additional-javascript

Author: fredericsimard

.htaccess

@@ -52,18 +52,6 @@ RewriteRule ^realtime/$ /documentation/overview/ [L,R=301]
 RewriteCond %{REQUEST_URI} ^/realtime/reference/$
 RewriteRule ^realtime/reference/$ /documentation/realtime/reference/ [L,R=301]
 
-# Anchor redirections
-RewriteRule ^realtime/process/#guiding-principles https://gtfs.org/community/governance/gtfs-realtime-amendment-process/#guiding-principles [R=301,NE]
-RewriteRule ^realtime/process/#revision-history https://gtfs.org/documentation/realtime/change-history/revision-history/ [R=301]
-RewriteRule ^realtime/process/#experimental-fields https://gtfs.org/community/governance/gtfs-realtime-amendment-process/#experimental-fields [R=301,NE]
-RewriteRule ^#why-use-gtfs https://gtfs.org/getting-started/why-use-GTFS/ [R=301]
-RewriteRule ^#what-is-high-quality-gtfs https://gtfs.org/getting-started/validate/ [R=301]
-RewriteRule ^schedule/#getting-started https://gtfs.org/getting-started/create/ [R=301]
-RewriteRule ^schedule/#training-resources https://gtfs.org/resources/overview/ [R=301]
-RewriteRule ^schedule/#getting-help-community https://gtfs.org/community/get-involved/ [R=301]
-RewriteRule ^schedule/process/#guiding-principles https://gtfs.org/community/governance/gtfs-schedule-amendment-process/#guiding-principles [R=301,NE]
-RewriteRule ^schedule/process/#revision-history https://gtfs.org/documentation/schedule/change-history/revision-history/ [R=301]
-
 # Redirect any URL containing underscores to the same URL with hyphens, plus correcting the file with spaces
 #RewriteCond %{THE_REQUEST} [_ ]
 #RewriteRule ^([^_]*)[_ ]([^_]*)$ $1-$2 [N]

mkdocs.yml

@@ -41,6 +41,8 @@ theme:
 extra_css:
   - assets/stylesheets/extra.css
   - assets/stylesheets/footer.css
+extra_javascript:
+  - assets/javascript/anchor-redirects.js
 extra:
   analytics:
     provider: google

overrides/assets/javascript/anchor-redirects.js

@@ -0,0 +1,17 @@
+const anchorMappings = {
+    '#guiding-principles': '/community/governance/gtfs-realtime-amendment-process/#guiding-principles',
+    '#revision-history': '/documentation/realtime/change-history/revision-history/',
+    '#experimental-fields': '/community/governance/gtfs-realtime-amendment-process/#experimental-fields',
+    '#why-use-gtfs': '/getting-started/why-use-GTFS/',
+    '#what-is-high-quality-gtfs': '/getting-started/validate/',
+    '#getting-started': '/getting-started/create/',
+    '#training-resources': '/resources/overview/',
+    '#getting-help-community': '/community/get-involved/',
+    '#schedule-guiding-principles': '/community/governance/gtfs-schedule-amendment-process/#guiding-principles',
+    '#schedule-revision-history': '/documentation/schedule/change-history/revision-history/',
+};
+
+const currentHash = window.location.hash;
+if (anchorMappings[currentHash]) {
+    window.location.href = anchorMappings[currentHash];
+}