This is V2 of https://github.com/scylladb/scylladb/pull/14108
This commit moves the installation instruction for the cloud from the [website ](https://www.scylladb.com/download/)to the docs.
The scope:
* Added new files with instructions for AWS, GCP, and Azure.
* Added the new files to the index.
* Updating the "Install ScyllaDB" page to create the "Cloud Deployment" section.
* Adding new bookmarks in other files to create stable links, for example, ".. _networking-ports:"
* Moving common files to the new "installation-common" directory. This step is required to exclude the open source-only files
in the Enterprise repository.
In addition:
- The Configuration Reference file was moved out of the installation
section (it's not about installation at all)
- The links to creating a cluster were removed from the installation
page (as not related).
Related: https://github.com/scylladb/scylla-docs/issues/4091
