fixup!: meta: add CONTRIBUTING.md

CONTRIBUTING.md

@@ -3,35 +3,38 @@ This document is a guide for contributions to the WGPU project.
 ## Welcome!
 
 First of all, welcome to the WGPU community! 👋 We're glad you want to
-contribute. If you are unfamiliar with the WGPU community as an organization, we
-recommend you read [`GOVERNANCE.md`] for an overview of how it works.
+contribute. If you are unfamiliar with the WGPU project, we recommend you read
+[`GOVERNANCE.md`] for an overview of its goals, and how it's governed.
 
 [`GOVERNANCE.md`]: ./GOVERNANCE.md
 
 ## Talking to other humans in the WGPU project
 
-The WGPU project has multiple ways to engage:
+The WGPU project has multiple official platforms for community engagement:
 
-- [GitHub discussions]: TODO: not sure when to use this over Matrix and issues.
-  TBH.
 - The Matrix channel [`wgpu:matrix.org`](https://matrix.to/#/#wgpu:matrix.org)
   is dedicated to informal chat about contributions the project. It is
   particularly useful for:
+
   - …saying hello, and introducing yourself.
   - …validating contributions (i.e., determining if they'll be accepted,
     ensuring your approach is correct, making sure you aren't wasting effort,
     etc.)
   - …setting expectations for contributions 
 
-  Notification in Matrix can sometimes be unreliable. Feel free to explicitly tag
-  people from whom you would like attention (but don't abuse it!), and follow-up
-  after a day or so if you do not get a response to your messages.
+  Notification in Matrix can sometimes be unreliable. Feel free to explicitly
+  tag people from whom you would like attention, esp. to follow-up after a day
+  or so if you do not get a response to your contributions.
 
-- [GitHub issues] are for action items that the community needs to prioritize.
-  These could be items of work resolved by pull requests, decisions to make with
-  a formal outcome, or collections of issues needed for a specific feature or
-  use case (AKA `[meta]` issues).
+- [GitHub issues] are for tasks that the community intends to work on.
+  We use these in several ways:
+  - Noting work that needs resolution via pull requests,
+  - Recording project decisions formally.
+  - Compiling sets of other issues needed for a specific feature or use case
+    (AKA `[meta]` issues).
 - [GitHub pull requests]: TODO
+- [GitHub discussions]: TODO: Experimentally used by some enthusiastic members
+  of our community. Not supported officially.
 
 [GitHub discussions]: https://github.com/gfx-rs/wgpu/discussions
 [GitHub issues]: https://github.com/gfx-rs/wgpu/issues
@@ -43,15 +46,38 @@ Community response to contributions are, in general, prioritized based on their
 relevance to WGPU's mission and decision-making groups' interest (see
 [`GOVERNANCE.md`]). 
 
-### "What can I work on?"
+### "What can I work on?" as a new contributor
 
 TODO
 
+We discourage new contributors from submitting large changes or opinionated
+refactors unless they have been specifically validated by WGPU maintainership.
+These are likely to be rejected on basis of needing discussion before a formal
+review.
+
 ### What to expect when you file an issue
 
 TODO
 
+- Describe the filing process
+  - Link to new issue page
+  - Describe how to socialize the issue effectively
+  - Feel free to ping us if it's a blocker!
+  - Suggesting tags is helpful.
+  - Describe how the project will handle the issue
+    - Our ability to respond to an issue depends entirely on whether it is
+      _actionable_ (viz., that there is a course of action that is reasonable
+      for a volunteer to take the time to do). If it's not actionable, we
+      reserve the right to close it. 
+      - Being responsive to requests for further information is important.
+      - Understanding what point in the repository's history an issue began is
+        also important. Maybe link to `git bisect` or something similar?
+      - In particular, expecting others to fix something hardware- or
+        driver-specific that current maintainership (1) can't mentor you
+        into fixing and (2) otherwise isn't being prioritized are likely to
+        be closed.
+
 ### What to expect when you submit a PR
 
-TODO: It is strongly recommended that you validate your contributions before you make
-significant efforts…
+TODO: It is strongly recommended that you validate your contributions before you
+make significant efforts…