clean up formatting and add missing closing tag
Merge branch 'patch-2' of github.com:gerbal/help.codecademy.com into keyboard-shortcuts

Conflicts:
	published/general/can-i-navigate-codecademy-courses-with-keyboard-shortcuts.md
update layouts and separate Codecademy specific and universal shortcuts into 2 tables
remove Chrome specific shortcut
add punctuation
update universal table text formatting
add mac+pc articles for shortcut article and remove combined article
recombine articles into single article and separate tables
add line break between links
update page formatting
add symbol key for mac shortcuts
fix table headers to be th instead of td
remove key and set new shortcut standard
add back some more os universal shortcuts helpful for text editing
add final shortcuts back to the document
rename tables as per discussion with @gerbal
Merge pull request #4 from sharocko/keyboard-shortcuts

revamp added shortcuts