Revamped snippets

Added

• #45 - Added owl snippets, Added few more snippets for xml and py, Revamped existing snippets, and many more.

Changed

• #38 - Added regex on few xml snippets. (Thanks @nhatnm0612)
• #38 - Added regex on few py snippets. (Thanks @jeffery9)

Removed

• #45 - Removed older js snippets.