Fix / keyboard shortcut to allow typing / within the search field

- Select all existing text in the field when pressing the shortcut.
- Remove broken Algolia integration (unused since 4.0) and move
  the shortcut code to the main `custom.js` file.

_static/js/algolia.js

@@ -1,27 +0,0 @@
-
-(function() {
-
-    var doc_version = document.querySelector('meta[name="doc_version"]').getAttribute('content');
-
-    // If the current page uses tabs, we will need this small patch
-    if (typeof(docsearch) == 'undefined') {
-        docsearch = exports['docsearch'];
-    }
-
-    // Initialize the Algolia search widget
-    docsearch({
-        apiKey: 'c39cb614363a2a156811478bc2d0573b',
-        indexName: 'godotengine',
-        inputSelector: '#rtd-search-form input[type=text]',
-        algoliaOptions: {
-            facetFilters: ["version:" + (doc_version || 'stable')]
-        },
-    });
-
-    window.addEventListener('keydown', function(event) {
-        if (event.key === '/') {
-            document.querySelector('#rtd-search-form input[type=text]').focus();
-            event.preventDefault();
-        }
-    })
-})();

_static/js/custom.js

@@ -246,6 +246,17 @@ $(document).ready(() => {
     Documentation.hideSearchWords();
   }
 
+  window.addEventListener('keydown', function(event) {
+    if (event.key === '/') {
+        var searchField = document.querySelector('#rtd-search-form input[type=text]');
+        if (document.activeElement !== searchField) {
+            searchField.focus();
+            searchField.select();
+            event.preventDefault();
+        }
+    }
+  });
+
   // Initialize handlers for page scrolling and our custom sidebar.
   const mediaQuery = window.matchMedia('only screen and (min-width: 769px)');
 

conf.py

@@ -217,9 +217,7 @@ if not on_rtd:
     html_css_files.append("css/dev.css")
 
 html_js_files = [
-    "js/custom.js?6", # Increment the number at the end when the file changes to bust the cache.
-    ('https://cdn.jsdelivr.net/npm/docsearch.js@2/dist/cdn/docsearch.min.js', {'defer': 'defer'}),
-    ('js/algolia.js', {'defer': 'defer'})
+    "js/custom.js?7", # Increment the number at the end when the file changes to bust the cache.
 ]
 
 # Output file base name for HTML help builder