message: add shortcut to documentation
diff: @@ -9,6 +9,7 @@ All commands are listed as <kbd>ctrl</kbd>+<kbd>some key</kbd>. If you're on Mac
  | Shortcut | Does |
  | ------------------------------------------- | ---------------------------------- |
  | <kbd>ctrl</kbd>+<kbd>alt</kbd>+<kbd>b</kbd> | Builds current file |
  +| <kbd>ctrl</kbd>+<kbd>alt</kbd>+<kbd>c</kbd> | clean latex build files |
  | <kbd>ctrl</kbd>+<kbd>alt</kbd>+<kbd>v</kbd> | Opens corresponding PDF |
  | <kbd>ctrl</kbd>+<kbd>alt</kbd>+<kbd>j</kbd> | Synctex from cursor (windows only) |
  | <kbd>ctrl</kbd>+<kbd>alt</kbd>+<kbd>x</kbd> | Open Extension Sidebar |
  