Merge pull request #301 from blinklabs-io/ci/code-coverage-diff

ci: show code coverage diff in PRs

Author: agaffney

.github/workflows/pr-coverage.yml

@@ -0,0 +1,21 @@
+# The below is copied from the upstream docs:
+# https://github.com/kskitek/coverdiff/blob/main/README.md
+
+name: Test coverage report
+concurrency:
+  cancel-in-progress: true
+  group: coverdiff-${{ github.ref }}
+
+on: [pull_request]
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  main:
+    name: Coverage
+    runs-on: ubuntu-latest
+    steps:
+    - name: Go cover diff
+      uses: kskitek/[email protected]