Unindent multi-line docstrings for command help

[nithinphilips]

When generating help for subcommands the docstring is used verbatim. The indentation used in the code often does not make sense in the context of command help.

Example

Given a command method:

# adding help to `foo` which is in the function signature:
@arg('foo', help='blah')
# these are not in the signature so they go to **kwargs:
@arg('baz')
@arg('-q', '--quux')
# the function itself:
def ting(foo, bar=1, *args, **kwargs):
    """
    Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
    tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
    veniam, quis nostrud.
    """
    pass

Generated help:

usage: ting [-h] [-b BAR] [-q QUUX]
            foo [args [args ...]] baz

    Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
    tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
    veniam, quis nostrud.


positional arguments:
  foo                   blah
[...]

Expected:

usage: ting [-h] [-b BAR] [-q QUUX]
            foo [args [args ...]] baz

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
veniam, quis nostrud.


positional arguments:
  foo                   blah
[...]

A possible solution may be to use the first line's indentation as a guide and remove that many characters.