Adds sublime-markdown-extended and sublime-monokai-extended, both also mapped to new names

"https://github.com/jonschlinkert/sublime-markdown-extended",
"https://github.com/jonschlinkert/sublime-monokai-extended",

Mapped to:

"sublime-markdown-extended": "Markdown Extended",
"sublime-monokai-extended": "Monokai Extended",