Expanded CONTRIBUTING doc

Add notes on voting, discussions etc., link to CoC.

CONTRIBUTING.md

@@ -1,14 +1,33 @@
 # Contributing to TeSS
 
-While TeSS was originally developed to serve as the training portal for [ELIXIR](https://www.elixir-europe.org/), it endeavours to be a generic platform that can be easily customized and re-used in other communities.
+While TeSS was originally developed to serve as the training portal for [ELIXIR](https://www.elixir-europe.org/), 
+it endeavours to be a generic platform that can be easily customized and re-used in other communities.
 
-There are numerous ways you can contribute to TeSS.
+This document outlines some of the ways in which you can contribute to TeSS.
 
-## Bug reports and suggestions
+### Before you begin
 
-We welcome anyone to submit bug reports and make feature suggestions on our [GitHub issues page](https://github.com/ElixirTeSS/TeSS/issues).
+If you plan on making a change to TeSS' code or documentation, it's a good idea to open an issue, or comment on an existing issue to explain and discuss why.
+This makes the TeSS contributors and members of the community aware of what activities are taking place, and lets them offer insight and advice.
 
-## Documentation
+You may also want to join the [TeSS Club](https://elixirtess.github.io/about/) - an open biweekly meeting to discuss the direction of TeSS' development.
+
+When contributing to TeSS you are expected to follow the [code of conduct](CODE_OF_CONDUCT.md). 
+
+## Bug reports and feature suggestions
+
+We welcome anyone to submit bug reports and make feature suggestions on our [GitHub issues page](https://github.com/ElixirTeSS/TeSS/issues). 
+Before opening a new issue, check to see if there is already an existing issue on the same subject.
+
+## Voting
+
+We encourage people to comment and vote on any issues and pull requests that they feel are important.
+
+Voting is done by commenting "+1" or "-1", or leaving a reaction (👍 for +1, 👎 for -1) on the original issue or pull request post.
+
+Community votes are non-binding, but help gauge opinion when prioritizing work.
+
+## Documentation contributions
 
 TeSS has various levels of documentation that can be contributed to:
 
@@ -20,7 +39,7 @@ Small changes can be made directly in GitHub, just open the relevant file, click
 
 For larger contributions, see the section below.
 
-## Code
+## Code contributions
 
 ### Fork TeSS
 
@@ -34,7 +53,7 @@ git remote add upstream https://github.com/ElixirTeSS/TeSS.git
 
 ### Create a feature branch
 
-Decide which branch do base your feature branch off. This will probably be `master` unless you are contributing a bug fix to a release of TeSS, in which case use e.g. `tess-1.2`.
+Decide which branch to base your feature branch off. This will probably be `master` unless you are contributing a bug fix to a release of TeSS, in which case use e.g. `tess-1.2`.
 
 Make sure your fork is up-to-date with upstream TeSS.
 
@@ -78,7 +97,7 @@ rubocop -a lib/my_code_that_i_wrote.rb
 
 Ensure your code is completely covered by test cases. Read through some existing tests to get an idea of how your code could be tested.
 
-Run the test suite to check your change has not broken any existing code. You can also see the test coverage % after the tests finish, make sure it has not decreased.
+Run the test suite to check your change has not broken any existing code. You can also see the test coverage % after the tests finish - make sure it has not decreased.
 
 ```
 bundle exec rails test
@@ -96,13 +115,18 @@ You can always [rebase](https://docs.github.com/en/get-started/using-git/about-g
 
 ### Open a Pull Request
 
-Go to your fork of TeSS on GitHub and select your feature branch. Click the 'Pull Request' button and fill out the form.
+Go to your fork of TeSS on GitHub and select your feature branch. Click the 'Pull Request' button and fill out the form. Make sure to include:
+ - A brief summary of what changes were made.
+ - Why the changes were made, with links to any issues.
+ - If appropriate, screenshots of the changes, or instructions on how the changes can be tried out.
+
+If your contribution is a work-in-progress, flag the pull request as being a "Draft".
 
-Your Pull Request should trigger a build that can be monitored on our [actions](https://github.com/ElixirTeSS/TeSS/actions) page.
+Your Pull Request should trigger a build that can be monitored on our [actions](https://github.com/ElixirTeSS/TeSS/actions) page. The core TeSS development team will also be notified, and a member of the team will review your Pull Request in a timely manner.  
 
 Check in from time to time, or wait for notifications of any reviewer comments or build failures.
 
-If you need to make additional code changes, just push them to your original branch and GitHub will update the open Pull Request.
+If you need to make additional code changes (in response to review comments, for example), just push them to your original branch and GitHub will update the open Pull Request.
 
-### Thanks!
+## Thanks!