build: setup OpenSSF Scorecard

Set up OpenSSF Scorecard to begin tracking security metrics within the repo.

(cherry picked from commit 2fb099c)

.github/workflows/scorecard.yml

@@ -0,0 +1,49 @@
+name: OpenSSF Scorecard
+on:
+  branch_protection_rule:
+  schedule:
+    - cron: '0 2 * * 0'
+  push:
+    branches: [master]
+  workflow_dispatch:
+
+# Declare default permissions as read only.
+permissions: read-all
+
+jobs:
+  analysis:
+    name: Scorecards analysis
+    runs-on: ubuntu-latest
+    permissions:
+      # Needed to upload the results to code-scanning dashboard.
+      security-events: write
+      actions: read
+      contents: read
+
+    steps:
+      - name: 'Checkout code'
+        uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # v2.4.0
+        with:
+          persist-credentials: false
+
+      - name: 'Run analysis'
+        uses: ossf/scorecard-action@c8416b0b2bf627c349ca92fc8e3de51a64b005cf # v1.0.2
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          repo_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_results: true
+
+      # Upload the results as artifacts.
+      - name: 'Upload artifact'
+        uses: actions/upload-artifact@82c141cc518b40d92cc801eee768e7aafc9c2fa2 # v2.3.1
+        with:
+          name: SARIF file
+          path: results.sarif
+          retention-days: 5
+
+      # Upload the results to GitHub's code scanning dashboard.
+      - name: 'Upload to code-scanning'
+        uses: github/codeql-action/upload-sarif@5f532563584d71fdef14ee64d17bafb34f751ce5 # v1.0.26
+        with:
+          sarif_file: results.sarif