Add initial doc comments processing

Supported sections without formatting: description, parameters,
returns, throws and additional info.

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
Add markdown support for doc description

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
Minor doc comments fixes

Typo, missing newline, missing start of code comment.

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
Set js code highlighting

Add js mark:

```js
code
```

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
Add styles for JS code highlighting

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>