ci: rework logic of terraform module documentation (#5)

.github/workflows/docs.yaml

@@ -2,11 +2,16 @@ name: Generate terraform docs
 on:
   - pull_request
 
+permissions:
+  contents: write
+  pull-requests: write
+
 jobs:
   docs:
     runs-on: ubuntu-latest
+    if: github.actor == 'dependabot[bot]'
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
         ref: ${{ github.event.pull_request.head.ref }}
 

.github/workflows/terraform.yaml

@@ -0,0 +1,21 @@
+name: Terraform
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+  terraform:
+    name: Terraform
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+
+    - name: Check terraform docs
+      uses: terraform-docs/gh-actions@v1.0.0
+      with:
+        fail-on-diff: true