release.md: Add missing argument.

release.md

@@ -9,7 +9,7 @@
   `tig --abbrev=12  --abbrev-commit 0.4.1..upstream/master`
 - Remove `-dev` suffix from `./.version`;
   Commit that using `git commit -m "Tag version $(<.version)." .version`;
-  Tag it using `git tag -s -m "Tag version $(<.version)"`;
+  Tag it using `git tag -s -m "Tag version $(<.version)" $(<.version)`;
   Increment `./.version` and restore the `-dev` suffix;
   Commit that using `git commit -C b5c30ae52638e81a38fe5329081c5613d7bd6ca5 .version`.
 - Push with `git push && git push --tags`