#2319 Add pull request template, w3c cepc, and shift some text around (#2320)

Patch by @ao5357

Author: ao5357

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,29 @@
+^ Please ensure the PR has a brief, yet descriptive name. [Delete this line]
+
+Changes related to issue #XXXX
+
+Ready for review by @username
+
+Replace this paragraph with a longer description of the changes made, such that a 
+reviewer can grasp what they will see before they open the diffs.
+
+--- Attribution --- [Delete this line and below if inapplicable] ---
+
+If you are not the sole contributor to a contribution (pull request), please identify all
+contributors in the pull request comment.
+
+To add a contributor (other than yourself, that's automatic), mark them one per 
+line as follows:
+
+```
++@github_username
+```
+
+If you added a contributor by mistake, you can remove them in a comment with:
+
+```
+-@github_username
+```
+
+Note: If you are making a pull request on behalf of someone else but you had no 
+part in designing the feature, you can remove yourself with the above syntax.

CODE_OF_CONDUCT.md

@@ -1,3 +1,5 @@
 # Code of Conduct
 
-All documentation, code and communication under this repository are covered by the [W3C Code of Ethics and Professional Conduct](https://www.w3.org/Consortium/cepc/).
+The CSS Working Group Editor Draft repository, being work of the 
+[World Wide Web Consortium (W3C)](https://www.w3.org/), is subject to the 
+[W3C Code of Ethics and Professional Conduct](https://www.w3.org/Consortium/cepc/).

CONTRIBUTING.md

@@ -1,38 +1,75 @@
-Contributions to this repository are intended to become part of Recommendation-track documents governed by the
-[W3C Patent Policy](https://www.w3.org/Consortium/Patent-Policy-20040205/) and
-[Software and Document License](https://www.w3.org/Consortium/Legal/copyright-software). To make substantive contributions to specifications, you must either participate
+# Contributor Guidelines
+
+Thank you for your interest in contributing to the [CSS Working Group](https://www.w3.org/Style/CSS/) 
+drafts!
+
+Contributions to this repository are intended to become part of Recommendation-track 
+documents governed by the: 
+
+  * [W3C Patent Policy](https://www.w3.org/Consortium/Patent-Policy-20040205/)
+  * [Software and Document License](https://www.w3.org/Consortium/Legal/copyright-software)
+
+To make substantive contributions to specifications, you must either participate
 in the relevant W3C Working Group or make a non-member patent licensing commitment.
 
-If you are not the sole contributor to a contribution (pull request), please identify all 
-contributors in the pull request comment.
+## Issue disclosure and discussion
+
+The first step for any contribution, substantive or not, is to either:
+
+  1. [Find an existing issue](https://github.com/w3c/csswg-drafts/issues) directly related to the contribution
+  2. [Add a new issue](https://github.com/w3c/csswg-drafts/issues/new)
+
+Issues are where individual reports and Working Group discussions come together such 
+that the eventual consensus can be turned into official specification language.
 
-To add a contributor (other than yourself, that's automatic), mark them one per line as follows:
+If you are familiar with a [GitHub-based pull request contribution workflow](https://help.github.com/articles/about-pull-requests/), 
+please note that **most issues are subject to quite a bit of discussion** before 
+draft language becomes ready for a pull request. Please ensure the full problem 
+space of the issue is explored in the discussion, and that consensus has been reached 
+by the participating members, before contributing to the 
+repository.
 
-```
-+@github_username
-```
+## Normative and/or substantive contributions
 
-If you added a contributor by mistake, you can remove them in a comment with:
+The CSS Working Group operates via the consensus of its membership, and discusses 
+all significant matters prior to implementation.
 
-```
--@github_username
-```
+If adding an new, normative issue, please label/tag the PR as 'Agenda+' to bring 
+it to the Working Group's attention.
 
-If you are making a pull request on behalf of someone else but you had no part in designing the 
-feature, you can remove yourself with the above syntax.
+The Working Group, aside from managing issues on GitHub, mainly discusses specifications 
+and requests on [the www-style public mailing list](https://lists.w3.org/Archives/Public/www-style/), 
+and in CSSWG meetings.
 
-# Tests
+### After discussion
+
+Once the Working Group has come to a consensus, a contributor may file a pull request 
+against the issue. The editor of the specification related to the issue will then be 
+responsible for reviewing both the content and implementation of the contributed 
+changes.
+
+Please follow the [Pull Request template](https://github.com/w3c/csswg-drafts/blob/master/.github/PULL_REQUEST_TEMPLATE.md) 
+when contributing to the repository.
+
+### Tests
 
 For normative changes for any specification in
 [CR or later](https://www.w3.org/Style/CSS/current-work) as well as the pre-CR specifications listed
 below, a corresponding [web-platform-tests](https://github.com/web-platform-tests/wpt) PR must be
 provided, except if testing is not practical; for other specifications it is usually appreciated.
+
 Typically, both PRs will be merged at the same time. Note that a test change that contradicts the
 spec should not be merged before the corresponding spec change. If testing is not practical, please
 explain why and if appropriate [file an issue](https://github.com/web-platform-tests/wpt/issues/new)
 to follow up later. Add the `type:untestable` or `type:missing-coverage` label as appropriate.
 
 The pre-CR specifications with this testing requirement are currently:
 
-* cssom
-* cssom-view
+  * cssom
+  * cssom-view
+
+## Non-substantive contributions
+
+For simple spelling, grammar, or markup fixes unrelated to the substance of a specification, 
+please file an issue with the usual shortname tagging (ie. `[css-foo]`) for the spec(s) 
+edited by the change. You may then issue a pull request referencing the issue number.