ci: Check consistency of generated files

This makes the .github/workflows/check-sourcecode
more a "check-repo" than a "check-sourcecode".

.github/workflows/check-sourcecode.yml

@@ -22,3 +22,21 @@ jobs:
 
       - name: "Check the sourcecode"
         run: ./tools/check-sourcecode
+
+  check-generated:
+    name: "Check Generated Files"
+    runs-on: ubuntu-latest
+
+    steps:
+
+      - uses: actions/checkout@v4
+
+      - name: Install prerequisites
+        run: >-
+          sudo apt-get update
+
+          sudo apt-get install -y
+          asciidoctor
+
+      - name: "Verify elf2tag.1 consistency"
+        run: ./src/update-elf2tag-manpage --verify