Add keys for direct room switching (#209)

* Add Keys.Rooms.Direct configuration

Keybinding to jump to specific room id in specific account id, or the
first occurence of specific room id in any account.

* Default binding was a bad idea

This example binding was preventing the user from binding Ctrl+G,Ctrl+M
to something else.

* Use const instead of var

* Use showItemAtIndex for direct room switching

This is a simpler implementation that better fits in the existing
codebase and doesn't really have drawbacks.

* Use existing findIndex

From roomList.model. Instead of reinventing it

* Made example not a real room

Earlier I made it point to the Mirage room

* Add instructions for copying room ID

After noticing that these IDs do not match Matrix room addresses, I felt
it was necessary to explain this here, even if it's already explained in
other parts of the configuration file.

* Use .split(" ") for splitting descriptions

This is a more readable implementation.

* Fix shortcuts breaking on config reload

Wrapping HShortcut in Loader makes it destructible.
See d53978f62bab35cdc7e115c50f0571f736814582

* Cleanup showRoomByDescription method, now showById

- "Room description" is a vague, it sounds like this is about
  the room topic too. Instead of having a function that takes a
  string with a certain format, take explicit arguments for the user and
  room ID, this way we don't need comments to explain what's going on
  either

- Reduce indentations and {} noise to make it simpler to read

* More details for direct room binds config comment

Co-authored-by: miruka <miruka@disroot.org>

src/config/settings.py

@@ -376,6 +376,17 @@ class Keys:
             9  = [Keys.alt_or_cmd() + "+9"]
             10 = [Keys.alt_or_cmd() + "+0"]
 
+        class Direct:
+            # Switch to specific rooms with keybindings.
+            # An unlimited number of properties can be added, where each
+            # property maps a room to a list of keybind.
+            # A room's ID can be copied by right clicking on it in the room list.
+            "!roomID:example.org" = []
+
+            # If you have multiple accounts in the same room, you can also set
+            # which account should be targeted as "<userId> <roomId>":
+            "@account:example.org !roomID:example.org" = []
+
     class Chat:
         # Keybinds specific to the current chat page.