Adjusts KeyRepeat & InitialKeyRepeat to be usable on macOS Sierra

Looks like they've changed the scale in macOS Sierrra. `KeyRepeat -int 0` seems to be too impractical. I can't even hold backspace because it erases too much. Since you've taken this from another repo, it's worth referencing the same issue in that repo:

mathiasbynens/dotfiles#687

bin/macos

@@ -56,7 +56,8 @@ defaults write NSGlobalDomain AppleFontSmoothing -int 2
 defaults write NSGlobalDomain ApplePressAndHoldEnabled -bool false
 
 # Set a blazingly fast keyboard repeat rate
-defaults write NSGlobalDomain KeyRepeat -int 0
+defaults write NSGlobalDomain KeyRepeat -int 1
+defaults write NSGlobalDomain InitialKeyRepeat -int 15
 
 # Disable auto-correct
 defaults write NSGlobalDomain NSAutomaticSpellingCorrectionEnabled -bool false