Add Dokka support

[dkhalanskyjb]

Fixes #192

[qwwdfsad]

Please note that #192 implies publication of the documentation as well

[dkhalanskyjb]

Certainly, I'll file a request to the kotlinlang.org team once this is merged.

[ilya-g]

I've noticed some error classes in the output, but probably it's because I'm building docs not on a Mac. Also there are parameter types that are not rendered as links to the types themselves in the declaration list, it's likely a bug in dokka, because these types are rendered fine in the declaration details.

[dkhalanskyjb]

For the record: https://youtrack.jetbrains.com/issue/KTL-841