Add workflow and script for updating changelog

.github/workflows/update-changelog.yml

@@ -0,0 +1,14 @@
+name: Update Changelog
+
+jobs:
+  release:
+    # Prevent this workflow from running elsewhere.
+    if: github.repository_owner == 'php-curl-class'
+
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Update list
+        run: python scripts/update_changelog.py

CHANGELOG.md

@@ -4,6 +4,8 @@ PHP Curl Class uses semantic versioning with version numbers written as `MAJOR.M
 `MINOR` and `PATCH` version changes. It is recommended to review `MAJOR` changes prior to upgrade as there may be
 backwards-incompatible changes that will affect existing usage.
 
+<!-- CHANGELOG_PLACEHOLDER -->
+
 ## 9.6.1 - 2022-06-30
 
 ### Fixed

scripts/update_changelog.py

@@ -0,0 +1,34 @@
+from datetime import datetime
+from pathlib import Path
+
+
+CURRENT_FILE = Path(__file__)
+ROOT = CURRENT_FILE.parents[1]
+
+
+def main():
+    # TODO: Fetch actual semantic version.
+    release_version = '9.6.2'
+    release_date = datetime.today().strftime('%Y-%m-%d')
+    release_title = '{} - {}'.format(release_version, release_date)
+
+    # TODO: Fetch actual list of changes.
+    release_changes = 'Some change'
+    release_content = (
+        '## {}\n'
+        '\n'
+        '{}'
+    ).format(release_title, release_changes)
+
+    changelog_path = ROOT / 'CHANGELOG.md'
+    old_content = changelog_path.read_text()
+    new_content = old_content.replace(
+        '<!-- CHANGELOG_PLACEHOLDER -->',
+        '<!-- CHANGELOG_PLACEHOLDER -->\n\n{}'.format(release_content),
+    )
+    print(new_content[:500])
+    changelog_path.write_text(new_content)
+
+
+if __name__ == '__main__':
+    main()