Add .copywrite.hcl and related GH workflow

.copywrite.hcl

@@ -0,0 +1,14 @@
+schema_version = 1
+
+project {
+  license        = "MPL-2.0"
+  copyright_year = 2017
+  header_ignore  = [
+    ".changelog/**",
+    ".github/**",
+    ".goreleaser.yml",
+    ".markdownlint.yml",
+    ".release/**",
+    "vendor/**",
+  ]
+}

.github/workflows/hc-copywrite.yml

@@ -0,0 +1,25 @@
+name: HashiCorp Copywrite
+
+on:
+  schedule:
+    - cron: '30 2 * * *'
+  pull_request:
+    branches:
+      - main
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+jobs:
+  copywrite:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
+
+    - name: Install copywrite
+      uses: hashicorp/setup-copywrite@3ace06ad72e6ec679ea8572457b17dbc3960b8ce # v1.0.0
+
+    - name: Validate Header Compliance
+      run: copywrite headers --plan