ci: update dependency install in pre-commit workflow

.github/workflows/pre-commit.yaml

@@ -33,6 +33,14 @@ jobs:
         python -m pip install --upgrade pip
         pip install pre-commit
 
+    - name: Installl terraform-docs
+      run: |
+        curl -sSLo ./terraform-docs.tar.gz https://terraform-docs.io/dl/v0.18.0/terraform-docs-v0.18.0-$(uname)-amd64.tar.gz
+        tar -xzf terraform-docs.tar.gz
+        chmod +x terraform-docs
+        mv terraform-docs /some-dir-in-your-PATH/terraform-docs
+
+
     - name: Install tflint
       run: |
         curl -s https://raw.githubusercontent.com/terraform-linters/tflint/master/install_linux.sh | bash