Replace antsibull-lint collection-docs with antsibull-docs lint-collection-docs. (#432) (#433)

(cherry picked from commit bc00c30faf)

Co-authored-by: Felix Fontein <felix@fontein.de>

tests/sanity/extra/extra-docs.py

@@ -14,7 +14,7 @@ def main():
     """Main entry point."""
     if not os.path.isdir(os.path.join('docs', 'docsite')):
         return
-    p = subprocess.run(['antsibull-lint', 'collection-docs', '.'], check=False)
+    p = subprocess.run(['antsibull-docs', 'lint-collection-docs', '.'], check=False)
     if p.returncode not in (0, 3):
         print('{0}:0:0: unexpected return code {1}'.format(sys.argv[0], p.returncode))