Update branch explanations and semver-ish automation

given move to main as v3

.github/workflows/cli.yml

@@ -46,11 +46,8 @@ jobs:
       - if: matrix.go == '1.19.x' && matrix.os == 'ubuntu-latest'
         run: make generate
       - run: make diffcheck
-      # TODO: switch once v3 is released {{
-      # - if: matrix.go == '1.19.x' && matrix.os == 'ubuntu-latest'
-      - if: 'false'
-        run: make v2diff
-      # }}
+      - if: matrix.go == '1.19.x' && matrix.os == 'ubuntu-latest'
+        run: make v3diff
       - if: success() && matrix.go == '1.19.x' && matrix.os == 'ubuntu-latest'
         uses: codecov/codecov-action@v3
         with:
@@ -78,7 +75,7 @@ jobs:
   publish:
     permissions:
       contents: write
-    # TODO: switch once v3 is released {{
+    # TODO: switch once v3 is out of alpha {{
     # if: startswith(github.ref, 'refs/tags/')
     if: 'false'
     # }}