Add CONTRIBUTING.md

[GaryJones]

Add a CONTRIBUTING.md file, and link to it from the readme, so potential contributors can be guided as to how they can make changes for PRs. It should cover how to export the updated XML file.

[manovotny]

@GaryJones : :

Do you have any personal preference or best practice to share as to whether this should be a standalone CONTRIBUTING.md or just included as a section in the README.md?

[GaryJones]

Since GitHub adds a big yellow banner for New Issues / new PRs when it detects a CONTRIBUTING.md, then I'd go with that, and a:

## Contributing

See the [guidelines for contributions](CONTRIBUTING.md).

... in the README.

The advantage to putting LICENSE, CONTRIBUTING.md, CHANGELOG.md and other bits in separate files, is that one can update without polluting the commit history of another.

[manovotny]

@GaryJones : :

I had no idea that GitHub added a yellow banner based on the existence of that file. That's pretty fantastic!

@tommcfarlin suggested the same linking to the CONTRIBUTING.md from the README.md, but he was just to shy to say it publicly. Great minds...

Thanks for the tips!

[manovotny]

@GaryJones : :

Just wanted to say thanks again for all you help on this and some of the other prodding on other issues.

The CONTRIBUTING.md file also points out why (I believe) simply editing the XML file directly is not possible. If that sounds bogus to you, then let me know if you have any other tips / tricks.

[GaryJones]

The description in CONTRIBUTING.md is the same conclusion I had drawn unfortunately. It would be nice if the exporter could be changed so the line-endings were consistent throughout the file (#22279?). In the meantime, hopefully the CONTRIBUTING.md will save someone a bit of time and not discovering this themselves.

Wait - @tommcfarlin - shy?! ;-)

[manovotny]

@GaryJones : :

As to your question on the code review... I would love to fix the root cause and one would think it should be solvable.

I appreciate you taking the time to find that trac issue and mention WP Test on it.