chore: Update Docusaurus deployment workflow and documentation structure

- Added a step to copy screenshots to the static directory during deployment.
- Updated .gitignore to keep the README file in the screenshots directory.
- Added a new README file in the screenshots directory to explain its purpose and usage.
- Introduced a new npm script to prepare screenshots for the documentation site.

docs/.gitignore

@@ -18,3 +18,6 @@
 npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
+
+# Keep the screenshots directory README
+!/static/screenshots/README.md