Feature request: Showing currently selected function signature.

[luckcolors]

Hello.
This is more like a question if it would be easy to do this.
So it's fine if you don't have the time to implement this i mainly would like help in implementing it myself (maybe by forking your extension).

This is a feature from atom where wenever you move the cursor over a function, you can see the full function signature definition.

Example situation:

function something (thing, otherthing) {
    return thing
}

function main() {
    something|()
}

For example if i put the cursor where the | is i would see on the bottom bar "function something (thing, otherthing)" wich is the definition of the function that i am calling over there.