Add recipe for rstcheck

[kynan]

Checklist

• Title of this PR is meaningful: e.g. "Adding my_nifty_package", not "updated meta.yaml"
• License file is packaged (see here for an example)
• Source is from official source
• Package does not vendor other packages. (If a package uses the source of another package, they should be separate packages or the licenses of all packages need to be packaged)
• If static libraries are linked in, the license of the static library is packaged.
• Build number is 0
• A tarball (url) rather than a repo (e.g. git_url) is used in your recipe (see here for more details)
• GitHub users listed in the maintainer section have posted a comment confirming they are willing to be listed there

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipes/rstcheck) and found it was in an excellent condition.

[kynan]

@conda-forge/help-python no idea why the build fails on Windows. Something appears to go wrong linking the entry-point executable?

[scopatz]

@kynan - It is noarch python, so it only needs to run on linux

[kynan]

Adding the entrypoint fixed this, thanks Anthony! I believe this is now good to go @conda-forge/help-python

[marcelotrevisani]

Can we add pip check here please?

Suggested change

	- python -m rstcheck --help
	- python -m rstcheck --help
	- pip check
	requires:
	- pip

[kynan]

Sorry, didn't see this in time. Added now!