Use GDScript-style return type in function prototypes in the integrated docs

[mieldepoche]

I can't unsee it, methods return types are C-style (type function()) but arguments are GDScript-style (arg: Type).
Does it make it easy to catch the return type at a glance? Does it date from a time where GDScript didn't support specifying return types?
I think it would be better to use the GDScript syntax for the GDScript docs.

current	new

I guess it makes sense in the methods summary, but idk...

[dalexeev]

I think return type alignment in the table is more important.

[timothyqiu]

Maybe keep the return type as separate column in the table, but use -> in the function description header?

[Calinou]

In my experience, the C-style signature style is more universally understood overall, and it's more relevant for C# users (and most GDExtension users). I'd keep it as-is for that reason.