chore: add OpenSSF Scorecard

.github/workflows/scorecard.yml

@@ -0,0 +1,21 @@
+name: Scorecard
+on:
+  branch_protection_rule:
+  schedule:
+    - cron: "42 4 * * MON"
+  push:
+    branches:
+      - main
+
+permissions: {}
+
+jobs:
+  scorecard:
+    name: Scorecard
+    permissions:
+      contents: read
+      id-token: write
+      security-events: write
+    uses: UpCloudLtd/workflows/.github/workflows/openssf-scorecard.yaml@main
+    with:
+      publish-results: true

README.md

@@ -3,6 +3,7 @@
 [![test](https://github.com/UpCloudLtd/upcloud-python-api/actions/workflows/main.yml/badge.svg)](https://github.com/UpCloudLtd/upcloud-python-api/actions/workflows/main.yml)
 [![PyPI version](https://badge.fury.io/py/upcloud-api.svg)](https://badge.fury.io/py/upcloud-api)
 [![License](https://img.shields.io/badge/license-MIT-green.svg)](https://github.com/UpCloudLtd/upcloud-python-api/blob/main/LICENSE.txt)
+[![OpenSSF Scorecard](https://api.scorecard.dev/projects/github.com/UpCloudLtd/upcloud-python-api/badge)](https://scorecard.dev/viewer/?uri=github.com%2FUpCloudLtd%2Fupcloud-python-api)
 
 OOP-based API client for [UpCloud's API](https://developers.upcloud.com/1.3/). Includes most of the API
 functionality and some convenience functions that combine several API endpoints and logic.