updated readme, security

[bidi47]

No description provided.

[bidi47]

before i make updates to the other branches, we should double-check the current update and the open items below

• are we marking any branch as archived or maintenance?
• does branch 4.0 need the docs folder?
• is it ok to copy-paste the readme contents into the docs/book/index.md for branch 3.0 to prevent the current linting error?

[arhimede]

before i make updates to the other branches, we should double-check the current update and the open items below

* are we marking any branch as archived or maintenance?

* does branch 4.0 need the docs folder?

* is it ok to copy-paste the readme contents into the docs/book/index.md for branch 3.0 to prevent the current linting error?

• make 3.0 maintenance
• delete the folder docs from branch 3.0
• delete the mkdocs and the workflow from 3.0