DOC: Attempt at autoformatting docstrings in morphology/*

[Carreau]

Numpydoc is specific about the meaning of spaces arround : and a few
other things, while it may look almost identical in sphinx depending on
themes it is semantically different.

I'm attempting to write an docstring autoreformatter thetry to fix
common mistakes, and fix a couple of other things like typo in parameter
names, remove parameters that are still documented, and try to get a
uniform style.

You'll see in the diff

• add / removal of spaces
• add / removal of blank lines
• indent 4 spaces always.
• Capitalisation of section names
• removal of border_value parameter which is indeed not a function
  argument.

In morphology/* this hasn't found any other issue it can fix, and the
only other non-automatically fixable issues are missing documentation
for dtype parameters.

For reviewers

• Check that the PR title is short, concise, and will make sense 1 year
  later.
• Check that new functions are imported in corresponding __init__.py.
• Check that new features, API changes, and deprecations are mentioned in
  doc/release/release_dev.rst.

[sciunto]

Great! Thank you for trying on our source files. The failure is related to #5318

[grlee77]

This is great, thanks! I commented on one inserted space that looked strange to me.

For context, I think these were generated with @Carreau's velin

[grlee77]

I think this extra space is unexpected?

[grlee77]

It does not cause any problem in the rendered doc: https://1635-2014929-gh.circle-artifacts.com/0/doc/build/html/api/skimage.morphology.html#skimage.morphology.convex_hull_object

[sciunto]

I interpreted it as a convention to split between arguments before * and after. Just a guess that I found elegant.

[Carreau]

I don't believe there are written rules about this; wether to put blank lines between items varies across projects; currently my auto formatter has some heuristics, in particular if one items description have multiple paragraph (which is the case here for connectivity) it will add one line between all items.

It is quite hard to no modify whitespace as is does Docstring -> AST-Like repr -> back to text, tso initial whitespace information is lost.

[Carreau]

I reran it with the --compact option to keep blank line to a minimal, this removed the line you pointed to.