This will correctly move text selection after using ctrl+shift+l to
insert link markdown when text is already selected in the editor. If
no text is selected when using hotkey, the proper markdown is inserted
and the cursor is moved so user can immediately start entering link
text.

Closes #2614
- When no text is selected insert link markdown and move cursor to a into the [] portion.
- When text is selected insert link markdown and move selection to http:// text so proper link can be pasted right away.