fixup! doc: use markdown when branch-diff major release

Author: RafaelGSS

doc/contributing/releases.md

@@ -1420,7 +1420,7 @@ The commits in the generated changelog must then be organized:
 * Separate all SEMVER-MAJOR, SEMVER-MINOR, and SEMVER-PATCH commits into lists
 
 ```console
-$ branch-diff upstream/vN-1.x upstream/vN.x --require-label=semver-major --group --filter-release --mardown # get all majors
+$ branch-diff upstream/vN-1.x upstream/vN.x --require-label=semver-major --group --filter-release --markdown # get all majors
 $ branch-diff upstream/vN-1.x upstream/vN.x --require-label=semver-minor --group --filter-release --markdown # get all minors
 $ branch-diff upstream/vN-1.x upstream/vN.x --exclude-label=semver-major,semver-minor --group --filter-release --markdown # get all patches
 ```