ci: run tests on push

Also, only generate vimdocs when on `main`

.github/workflows/modicator.yml

@@ -2,6 +2,7 @@ name: panvimdoc
 on: [push]
 jobs:
   docs:
+    if: github.ref == 'refs/heads/main'
     runs-on: ubuntu-latest
     name: pandoc to vimdoc
     steps:
@@ -14,3 +15,21 @@ jobs:
         with:
           commit_message: "docs: auto generate vimdoc"
           branch: ${{ github.head_ref }}
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install Neovim
+        shell: bash
+        run: |
+          mkdir -p /tmp/nvim
+          wget -q https://github.com/neovim/neovim/releases/download/nightly/nvim.appimage -O /tmp/nvim/nvim.appimage
+          cd /tmp/nvim
+          chmod a+x ./nvim.appimage
+          ./nvim.appimage --appimage-extract
+          echo "/tmp/nvim/squashfs-root/usr/bin/" >> $GITHUB_PATH
+      - name: Run Tests
+        run: |
+          nvim --version
+          [ ! -d tests ] && exit 0
+          nvim --headless -c "PlenaryBustedDirectory tests/"