Improved syntax highlighting for types with "where" in hovers

[filiptibell]

Generic types in hovers sometimes get expanded like this:

local foo: t2 where t1 = {
    Connect: (self: t1) -> boolean,
    Destroy: (self: t1) -> boolean,
    Disconnect: (self: t1) -> boolean
} ; t2 = {
    Bar: t1,
}

It seems like the where breaks syntax highlighting here

[JohnnyMorganz]

This syntax is somewhat annoying. Contributions welcome in https://github.com/JohnnyMorganz/Luau.tmLanguage to support it