Add support for (github) emoji

[mindplay-dk]

Github markdown includes support for emoji. Currently these are not rendered.

Consider adding support for emoji, for example via this library:

https://github.com/iamcal/js-emoji

Note that this is just an example - there are many, and I don't mean to recommend a specific library.

[ShyykoSerhiy]

You can use emoji right now if you insert them Emoji & Symbols in Intellij

or if you copy them for example from http://getemoji.com/ . But I'll have a look to support :someemoji: format.

[hohserg1]

i'm don't have that

[hohserg1]

I'm try to off offline generation. Without offline generation(screenshot) With offline generation In first case image in local folder are not rendered In second case not rendered emoji