Add neovim related workflows

.github/workflows/update.yaml

@@ -10,6 +10,8 @@ jobs:
     steps:
       - name: Checkout repository
         uses: actions/checkout@v2
+        with:
+          token: ${{ secrets.GH_TOKEN_FOR_UPDATES }}
       - name: Install Nix
         uses: cachix/install-nix-action@v20
         with:
@@ -20,8 +22,15 @@ jobs:
         uses: DeterminateSystems/update-flake-lock@v16
         with:
           pr-title: "Update flake.lock"
-      - uses: juliangruber/merge-pull-request-action@v1
+          token: ${{ secrets.GH_TOKEN_FOR_UPDATES }}
+      - uses: actions-ecosystem/action-add-labels@v1
         with:
-          github-token: ${{ secrets.GITHUB_TOKEN }}
+          labels: automerge
           number: ${{ steps.update.outputs.pull-request-number }}
-          method: rebase
+      - name: Update nvim-treesitter
+        run: |
+          git checkout update_flake_lock_action
+          nix run .\#update-nvim-treesitter -- neovim/nvim-treesitter
+          git add neovim/nvim-treesitter
+          git commit -m "neovim: Update nvim-treesitter parsers"
+          git push