Inheritance for method docs from parent trait

[mlange-42]

Allows to transclude method docs from a trait into a struct method:

trait MyTrait:
    fn do_something(self) -> Int:
        """
        A method that returns an integer.

        Returns:
            An arbitrary integer.
        """
        ...

@value
struct MyStruct(MyTrait):
    fn do_something(self) -> Int:
        """See [[.MyTrait]]."""
        return 100

The signature of the method must be the same as in the trait. So aliases can't be used if the trait does not use them.

Fixes #207

[coveralls]

Pull Request Test Coverage Report for Build 13169748637

Details

• 149 of 203 (73.4%) changed or added relevant lines in 5 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.6%) to 72.118%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/document/paths.go	48	49	97.96%
internal/document/processor.go	4	6	66.67%
internal/document/render.go	1	3	33.33%
internal/document/links.go	24	27	88.89%
internal/document/transclude.go	72	118	61.02%

Totals
Change from base Build 13169167303:	-0.6%
Covered Lines:	1733
Relevant Lines:	2403

---

💛 - Coveralls