Add default to formatted annotation

[flying-sheep]

WIP.

Fixes #48

[flying-sheep]

I don’t understand how my changes cause this:

>           assert text_contents == expected_contents
E           assert 'Dummy Module...     "None"\n' == 'Dummy Module...     "None"\n'
E             Skipping 3774 identical leading characters in diff, use -v to show
E             -    **x** (Callable[[int, bytes], int] (default: "None")) -- foo
E             +    **x** (*Callable**[**[**int**, **bytes**]**, **int**]* (default: "None")) -- foo
E             ?           +        ++ ++ ++   ++  ++     ++ ++  ++   ++ +
E               
E                     Return type:
E                        ClassWithTypehintsNotInline...
E             
E             ...Full output truncated (20 lines hidden), use '-vv' to show

[gaborbernat]

This seems very outdated now, I'll close this as such, but we can reopen a new PR if we figure this one out.

[flying-sheep]

I re-did the PR: #191

Would be nice if you could take a look this time.