[Enhancement] Keep old version documents as they were

1. ~~The `Installation and deployment` and `SDK` category should be in front of the `Design documents` category.~~ (completed in https://github.com/apache/eventmesh-site/pull/152)

2. Older versions of the documentation should remain as they were in the Git repository at the time of each release.