protector: add page (#5820)

pages/common/protector.md

@@ -0,0 +1,16 @@
+# protector
+
+> Protect or unprotect branches on GitHub repositories.
+> More information: <https://github.com/jcgay/protector>.
+
+- Protect branches of a GitHub repository (create branch protection rules):
+
+`protector {{branches_regex}} -repos {{organization/repository}}`
+
+- Use the dry run to see what would be protected (can also be used for freeing):
+
+`protector -dry-run {{branches_regex}} -repos {{organization/repository}}`
+
+- Free branches of a GitHub repository (delete branch protection rules):
+
+`protector -free {{branches_regex}} -repos {{organization/repository}}`