feat: add documentation → type:documentation label migration

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: EMaher

.github/workflows/issue-labels-sync.yml

@@ -165,7 +165,8 @@ jobs:
             const MIGRATIONS = [
               { from: 'bug', to: 'type:bug' },
               { from: 'question', to: 'type:question' },
-              { from: 'enhancement', to: 'type:enhancement' }
+              { from: 'enhancement', to: 'type:enhancement' },
+              { from: 'documentation', to: 'type:documentation' }
             ];
 
             for (const { from, to } of MIGRATIONS) {