add shfmt to lint.yml

.github/workflows/lint.yml

@@ -16,3 +16,11 @@ jobs:
     - uses: actions/checkout@v2
     - name: run shellcheck
       uses: ludeeus/action-shellcheck@1.1.0
+    
+    - name: run shfmt
+      uses: luizm/action-sh-checker@v0.3.0
+      env:
+        SHFMT_OPTS: -i 4 -d
+      with:
+        sh_checker_comment: false
+        sh_checker_shellcheck_disable: true