Updating README to mention Discussions

README.md

@@ -2,16 +2,19 @@
 
 This repository is a catalog of proposed and in-progress enhancements to Cantera. It serves as a resource for understanding what features are desired by the Cantera user community, and the projects that are being undertaken to improve Cantera's capabilities.
 
+We’re currently trying out GitHub's "Discussions" feature on this repository in addition to the Issue tracker interface. I expect there is some learning to be done about how to best use this repository, but for now, don't worry too much about what the best place to start a particular topic is. We can convert existing Issues into Discussions if they would benefit from this format, and if a Discussion leads to a more concrete idea for implementation or turns into a work in progress, that can be summarized in a new Issue, linked to the preceeding Discussion.
+
 ## Feature requests
-* Enhancements to Cantera can be proposed by creating a new issue in this repository using the "Feature request" template.
-* The issue will serve as a place to discuss the proposed feature addition and its possible implementations.
-* The Cantera maintainers may edit the initial post in each feature request to reflect updates based on the discussion 
-* These feature request issues can also be used to help potential contributors find projects to work on.
+* Enhancements to Cantera can be proposed by creating a new issue in this repository using the "Feature request" template, or as a new "Idea" discussion.
+* The issue/discussion will serve as a place to discuss the proposed feature addition and its possible implementations.
+* The Cantera maintainers may edit the initial post in each feature request to reflect updates based on the discussion. 
+* These feature request issues/discussions can also be used to help potential contributors find projects to work on.
 
 ## Work in progress
-* If you are working on a new feature or other major update to Cantera, you are encouraged to create a new issue in this repository using the "Work in progress" template
-* This issue will serve as a way of notifying other developers and users that this work is being done so that efforts can be coordinated and duplicate work can be avoided
-* The issue can also be used to discuss the implementation at an early stage and make sure that it is being done in a way that will lead to acceptance of the eventual pull request
+* If you are working on a new feature or other major update to Cantera, you are encouraged to create a new issue or discussion in this repository using the "Work in progress" template
+* A work in progress issue will serve as a way of notifying other developers and users that this work is being done so that efforts can be coordinated and duplicate work can be avoided
+* Creating a discussion of the implementation at an early stage is encouraged to help shape the work and make sure that it is being done in a way that will lead to acceptance of the eventual pull request
+* For external projects that are related to Cantera (for example, ones that depend on Cantera) but are not expected to be made part of Cantera, the "show and tell" discussion category is appropriate.
 
 ## General
 * When an implementation of a new feature is ready, a pull request for the [Cantera/cantera](https://github.com/cantera/cantera) repository should be created so the addition of the feature can be finalized.