Update data directory paths

[dnicolson]

This pull request updates the README to use the data directory path for Sublime Text 3 and later.

[rchl]

I would rather explain to find the path to the directory by running Preferences: Browse Packages from the Command Palette since even the updated paths will not always be correct. For example if the user has upgraded from ST3 then the paths will still point to the Sublime Text 3 directory.

[dnicolson]

Feel free to change it, I was mistaken that Sublime Text 3 uses ~/Library/Application Support/Sublime Text. It's only the application name that became "Sublime Text" in version 3.

[rchl]

Sublime Text 4 uses Sublime Text unless there already exists Sublime Text 3 then it uses that.

[rchl]

dd0cdcb