[DOP-27545] docs(mddocs): add en docs from docs_rework

[annamikhailovapsk]

Change Summary

Created en folder documentation with documents in markdown

Checklist

• Commit message and PR title is comprehensive
• Keep the change as small as possible
• Unit and integration tests for the changes exist
• Tests pass on CI and coverage does not decrease
• Documentation reflects the changes where applicable
• docs/changelog/next_release/..rst file added describing change (see CONTRIBUTING.rst for details.)
• My PR is ready to review.