feat: added doc comments on hover

[cadamsdev]

Supported features

Symbol location	Example	Supported
Same file — function	fn greet() in current file	✅
Same file — method	fn (mut app App) run()	✅
Same file — struct	struct Config {}	✅
Same file — enum	enum Color { red green }	✅
Same file — interface	interface Animal {}	✅
Same file — type alias	type Handler = fn()	✅
Same file — const	const max_retries = 3	✅
Other open project file	fn helper() in utils.v (open)	✅
Untracked project file	fn helper() in utils.v (not yet opened)	✅
V builtin	println, eprintln, len, etc.	✅
Imported stdlib module	os.read_file after import os	✅
Dotted stdlib module	v.util.SomeFunc after import v.util	✅
External package (non-vlib)	Third-party modules outside vlib/	❌
Struct fields	config.timeout	❌
Enum variants	Color.red	❌

Media

Functions from standard library

Constants

Function (single line comment)

Function (Multi-line comment)

Function that's being called

Function from another file (same module)

Structs

Interfaces