Contribution guide modify

[arshadkazmi42]

I want to point out that this readme is quite limiting because not all contributions have to be in the form of actual code, but also documentation, finding bugs, etc. Also I don't know about some of the steps:

1. git add --all. This is dependent on how extensive the .gitignore file is. I think it should say only add the actual files you purposely created or modified by having them check with git status first.
2. I think it would also be great if the doc included setting up an upstream from their local copy to this remote. ref https://akrabat.com/the-beginners-guide-to-contributing-to-a-github-project/.
3. This is a wonderful example of a contributing guide: https://github.com/ollelauribostrom/rebus

This should be opened in it's own issue though.

Originally posted by @cdrani in #62 (comment)