docs(watchers): add aw-watcher-gnome (#114)

Author: flexagoon

src/watchers.rst

@@ -58,6 +58,7 @@ Other watchers to collect all kinds of data.
 - :gh:`Edwardsoen/aw-watcher-steam` - A Watcher to monitor current game being played.
 - :gh:`2e3s/awatcher` - A compiled watcher for X11 and Wayland to replace the original active window and AFK watchers, with workarounds for KDE and Gnome on Wayland.
 - :gh:`RTnhN/aw-watcher-toggl` - A Watcher to import time entries from Toggl.
+- :gh:`flexagoon/aw-watcher-gnome` - A watcher to use ActivityWatch on GNOME with Wayland
 
 Custom visualizations
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