Update datatip display (issue and enhancement

[Et7f3]

issue part:
: is displayed %3A
double underscore are interpreted like markdown s
enhancement:
Can we display {!Make} as link to the actual doc of value Make ?
If not wan we emulate with some event (hover ?).
Or open a request feauture on rls to add such functionality.

[zaaack]

@Et7f3 This is an issue for upstream project atom-languageclient, looks atom-languageclient doesn't support rendering any link syntax in comment.