message: Update README for Mac key repeat
  * Update README for Mac key repeat
  I was having trouble getting my Mac to key repeat, I did some quick research and found The issue was that I had a global default that was true, which was overriding the application level `com.microsoft.VSCode` setting.
diff: @@ -53,6 +53,8 @@ If key repeating isn't working for you, execute this in your Terminal.
  ```sh
  defaults write com.microsoft.VSCode ApplePressAndHoldEnabled -bool false # For VS Code
  defaults write com.microsoft.VSCodeInsiders ApplePressAndHoldEnabled -bool false # For VS Code Insider
  +defaults delete -g ApplePressAndHoldEnabled # If necessary, reset global default
  +
  ```
  We also recommend going into *System Preferences -> Keyboard* and increasing the Key Repeat and Delay Until Repeat settings to improve your speed.
  