Create page "how to contribute" (dev, docs, tasks) as a first steps guide in SWH

When welcoming newcomers into the SWH community there should be a high level guide for the contribution workflow.

Here are the steps you should follow before applying, to make sure you have a good grasp of what we are doing at Software Heritage and how we do it:

1. Follow our getting started guide: it will make sure you can locally run a (small) copy of the archive and ingest source code into it
2. Create an account on our development forge
3. Familiarize yourself with our code review workflow
4. Make a simple change to any one of our software components and submit it as a diff for code review, following the above workflow. Easy hacks and Web UI issues are good options for what to fix, but feel free to submit any patch you think it might be useful. from GSoC 2019 page

How to do a diff on Code review page: https://wiki.softwareheritage.org/wiki/Code_review_in_Phabricator

other references: workflow: https://wiki.softwareheritage.org/wiki/External_contribution_integration legal: https://wiki.softwareheritage.org/wiki/Contributor_License_Agreement high level page: https://www.softwareheritage.org/community/developers/

---

Migrated from T2050 (view on Phabricator)