feat: support deep access

[numToStr]

This adds support for parsing deep-access objects. Previously, following code

local U = {}

---Foo
---@type table
U.foo = {}

---Bar
---@return table
function U.foo:bar()
    self.__index = self
    return setmetatable({}, self)
end

---Baz
---@return table
function U.foo.baz()
    return U.foo:bar()
end

return U

Was rendered as the following, look how bar() and baz() methods are missing.

U.foo                                                                    *U.foo*
    Foo

    Type: ~
        (table)


U.foo()                                                                  *U.foo*
    Bar

    Returns: ~
        (table)


U.foo()                                                                  *U.foo*
    Baz

    Returns: ~
        (table)

Now with this PR, it is rendered as expected

U.foo                                                                    *U.foo*
    Foo

    Type: ~
        (table)


U.foo:bar()                                                          *U.foo:bar*
    Bar

    Returns: ~
        (table)


U.foo.baz()                                                          *U.foo.baz*
    Baz

    Returns: ~
        (table)