docs: add zed watcher (#144)

Author: sachk

src/watchers.rst

@@ -45,6 +45,7 @@ Watches the actively edited file and associated metadata like path, language, an
 - :gh:`pytlus93/AwWatcherNetBeans82` - NetBeans 8.2, by :gh-user:`pytlus93`
 - :gh:`LordGrimmauld/aw-watcher-obsidian` - Obsidian.md extension, by :gh-user:`LordGrimmauld`
 - :gh:`lowitea/aw-watcher.nvim` - neovim extension, by :gh-user:`lowitea`.
+- :gh:`sachk/aw-watcher-zed` - Zed extension, by :gh-user:`sachk`.
 
 Media watchers
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