Language grammars Live Reload for Atom (Async)
Reload automatically editors when grammars files (.cson) changes.
The reloading is doing asynchronously.
Only editors that are affected by the selected language are reload.

Options
Enable live reload: check if you want to enabled grammars live reload.Disable live reload for specific grammars: define the names of your grammars package who exclude from live reload. (ex:language-git, language-swift)Regular expression use to detect grammar files
Install
Settings/Preferences > Install > Search for grammar-live-reload
Or
apm install grammar-live-reload