Update README.md

Add Bonusly to the list of services supporting emoji-cheat-sheet
Update index.html

Add Bonusly to the list
Merge pull request #175 from bonusly/master

Update README.md
Added Discourse to the list and small fixes
Merge pull request #176 from awesomerobot/master

Added Discourse to the list and small fixes
Adds :back: , :black_medium_small_square: , :black_small_square: , :package: , :sparkle: , :white_black_square: , :white_medium_small_square

Adds :back: , :black_medium_small_square: , :black_small_square: ,
:package: , :sparkle: , :white_black_square: ,
:white_medium_small_square: , :white_medium_square: ,
:white_small_square:
Adds :black_medium_square: and :white_medium_square:

Adds :black_medium_square: and :white_medium_square:
Removes duplicate "white_black_square" image from images folder

Removes duplicate "white_black_square" image from images folder
Merge pull request #180 from dlambl/master

Changes for issue #170