DOC: Update PR template and CONTRIBUTING.md

Author: threecgreen

.github/pull_request_template.md

@@ -1,6 +1,10 @@
-# Pull Request
+# Pull request
 
 Please include a summary of the changes.
+Please also include relevant motivation and context.
+List any dependencies that are required for this change.
+
+Fixes # (issue)
 
 ## Type of change
 
@@ -13,4 +17,22 @@ Please delete options that are not relevant.
 
 ## How has this change been tested?
 
-Please describe how this code was/is tested.
+Please describe the tests that you ran to verify your changes.
+Provide instructions so we can reproduce.
+Please also list any relevant details for your test configuration.
+
+- [ ] Test A
+- [ ] Test B
+
+## Checklist
+
+- [ ] My code builds locally with no new warnings (`scripts/build.sh`)
+- [ ] My code follows the [style guidelines](https://google.github.io/styleguide/cppguide.html)
+- [ ] New and existing unit tests pass locally with my changes (`scripts/test.sh`)
+- [ ] I have made corresponding changes to the documentation
+- [ ] I have added tests that prove my fix is effective or that my feature works
+
+## Declaration
+
+I confirm this contribution is made under an Apache 2.0 license and that I have the authority
+necessary to make this contribution on behalf of its copyright owner.

.github/workflows/build.yaml

@@ -3,6 +3,7 @@ name: build
 # Build and test databento-cpp
 
 on:
+  pull_request:
   push:
 
 jobs:

CONTRIBUTING.md

@@ -1,3 +1,4 @@
-We welcome feedback through discussions and issues on GitHub, however we don't currently accept pull requests due to the open-source repository being a downstream mirror of our internal codebase.
-
-Please direct email feedback to support@databento.com or carter@databento.com.
+Thank you for taking the time to contribute to our project.
+We welcome feedback through discussions and issues on GitHub, as well as our [community Slack](https://databento.com/support).
+While we don't merge pull requests directly due to the open-source repository being a downstream
+mirror of our internal codebase, we can commit the changes upstream with the original author.