composebox: Add typeahead for /todo.

Author: ganpa3

frontend_tests/node_tests/composebox_typeahead.js

@@ -1281,6 +1281,10 @@ run_test("begins_typeahead", () => {
     assert_typeahead_equals("abc/po", false);
     assert_typeahead_equals("hello /poll", false);
     assert_typeahead_equals("\n/pol", false);
+    assert_typeahead_equals("/todo", composebox_typeahead.slash_commands);
+    assert_typeahead_equals("my /todo", false);
+    assert_typeahead_equals("\n/to", false);
+    assert_typeahead_equals(" /tod", false);
 
     assert_typeahead_equals("x/", false);
     assert_typeahead_equals("```", false);

static/js/composebox_typeahead.js

@@ -394,6 +394,10 @@ exports.slash_commands = [
         text: i18n.t("/settings (Load settings menu)"),
         name: "settings",
     },
+    {
+        text: i18n.t("/todo (Create a todo list)"),
+        name: "todo",
+    },
 ];
 
 exports.filter_and_sort_mentions = function (is_silent, query, opts) {