README: Minor tweaks

The `defaults read` output is not valid JSON, so use a different file extension.
README: Minor tweaks

The `defaults read` output is not valid JSON, so use a different file
extension.
Merge branch 'patch-1' of https://github.com/mathiasbynens/OSXDefaults into pr/1
Merge branch 'master' of https://github.com/kevinSuttle/OSXDefaults into pr/1

Conflicts:
	README.md