Missing Emoji support

[ghost]

Since MarkRight is a GitHub flavoured MarkDown editor it should have Emoji support. :four_leaf_clover: :video_game: :pray:

Also thanks for this great tool!

[Drudoo]

Second this!

[dvcrn]

PRs are welcome 😄 I'm a bit short on time these days.

In general we can either use one of the finished js libraries that do this and pipe the text through it on change or write a manual parser that matches all :something: blocks