Split niri, hypr, fish into submodules; tmux, tmux-palette, television, yazi into externals

docs/desktop/niri.mdx

@@ -7,6 +7,8 @@ description: Scrollable-tiling Wayland compositor config — input, layout, wind
 
 :::note
 Linux `desktop` and `laptop` roles only. `.chezmoiignore.tmpl` skips `~/.config/niri/**`, `~/.local/bin/niri-launch`, and `~/.local/bin/cp-appid` on other roles. The `niri-launch-*` wrappers are not in the ignore list and are applied everywhere.
+
+`dot_config/niri` is a git submodule ([prdlk/niri](https://github.com/prdlk/niri)). Edit inside the submodule, commit there, then commit the updated pointer in the chezmoi repo.
 :::
 
 ## Files