fix(scripts): correct usage and help exit status (#143)

local/bin/x-gh-get-latest-version

@@ -97,7 +97,7 @@ Examples:
   # Use GitHub Enterprise API
   GITHUB_API_URL="https://github.example.com/api/v3/repos" $BIN ivuorinen/dotfiles
 EOF
-  exit 1
+  exit 0
 }
 
 # Check that required dependencies are installed

local/bin/x-mkd

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 #
 # Create a directory and cd into it
-# Usage: mkcd <dir>
+# Usage: x-mkd <dir>
 
 set -euo pipefail