**Restructure documentation layout, update entrypoint links, and migrate folders**
This commit introduces a consistent and modular documentation structure by
grouping related documentation under `libs`, `apis`, and `tutorials`. The
Dockerfile now reflects the new paths, and the index page links have been
adjusted accordingly.
### Folder Migrations
The following documentation directories were moved:
- `./mongo-ops/site` → `./libs/mongo-ops/site`
- `./blog-api/site` → `./apis/blog/site`
- `./tutorials/media-manager/site` (unchanged, retained under tutorials)
These changes improve namespace clarity and reflect the logical separation
between libraries, APIs, and tutorials.
### Additional Changes
- Updated URLs in `_index/index.html` to point to `/libs/mongo-ops/` and `/apis/blog/`.
- Removed outdated root-level documentation folders.
