recent_topics: Focus on search box on `t` keypress.

static/js/hotkey.js

@@ -477,6 +477,7 @@ exports.process_hotkey = function (e, hotkey) {
         case "vim_right":
         case "tab":
         case "shift_tab":
+        case "open_recent_topics":
             if (
                 ["#recent_topics", "#", ""].includes(window.location.hash) &&
                 !popovers.any_active() &&

static/js/recent_topics.js

@@ -600,6 +600,9 @@ exports.change_focused_element = function (e, input_key) {
         // wraparound.  Going off the top or the bottom takes one
         // to the navigation at the top (see set_table_focus).
         switch (input_key) {
+            case "open_recent_topics":
+                set_default_focus();
+                return true;
             case "shift_tab":
             case "vim_left":
             case "left_arrow":

static/templates/recent_topics_table.hbs

@@ -3,7 +3,7 @@
         {{> recent_topics_filters}}
     </div>
     <div class="search_group" role="group">
-        <input type="text" id="recent_topics_search" value="{{ search_val }}" placeholder="{{t 'Search stream / topic' }}">
+        <input type="text" id="recent_topics_search" value="{{ search_val }}" placeholder="{{t 'Search stream / topic (t)' }}">
         <button type="button" class="btn clear_search_button" id="recent_topics_search_clear">
             <i class="fa fa-remove" aria-hidden="true"></i>
         </button>

templates/zerver/app/keyboard_shortcuts.html

@@ -243,6 +243,10 @@
                     <td class="definition">{% trans %}View recent topics{% endtrans %}</td>
                     <td><span class="hotkey"><kbd>T</kbd> or <kbd>Esc</kbd> or <kbd>Ctrl</kbd> + <kbd>[</kbd></span></td>
                 </tr>
+                <tr>
+                    <td class="definition">{% trans %}Search recent topics{% endtrans %}</td>
+                    <td><span class="hotkey"><kbd>T</kbd></span></td>
+                </tr>
             </table>
         </div>
         <div>

templates/zerver/help/keyboard-shortcuts.md

@@ -140,6 +140,7 @@ title="thumbs up"/>**: `+`
 ## Recent topics
 
 * **View recent topics**: `t` or `Esc` or `Ctrl` + `[`
+* **Search recent topics**: `t`
 
 Keyboard navigation (e.g. arrow keys) works as expected.
 Use `Enter` to engage with elements.