Moving bitwarden_rs outside Bitwarden section

Since bitwarden_rs is a full implementation of the Bitwarden API and has no
dependencies with the official project, it was moved to be a main entry from
the Password Managers section.

README.md

@@ -1082,7 +1082,7 @@ See https://github.com/n1trux/awesome-sysadmin#monitoring and https://github.com
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 - [Bitwarden](https://bitwarden.com/) - Password manager with webapp, browser extension, and mobile app. ([Source Code](https://github.com/bitwarden/core)) `AGPL-3.0` `C#`
-  - [bitwarden_rs](https://github.com/dani-garcia/bitwarden_rs) - Lightweight Bitwarden server API implementation written in Rust. `GPL-3.0` `Rust`
+- [bitwarden_rs](https://github.com/dani-garcia/bitwarden_rs) - Lightweight Bitwarden server API implementation written in Rust. `GPL-3.0` `Rust`
 - [keeweb](https://keeweb.info/) - This webapp is a browser and desktop password manager compatible with KeePass databases. ([Source Code](https://github.com/keeweb/keeweb)) `MIT` `HTML5`
 - [Passbolt](https://www.passbolt.com/) - Password manager dedicated for managing passwords in a collaborative way on any Web server, using a MySQL database backend. ([Source Code](https://github.com/passbolt/passbolt_api)) `AGPL-3.0` `PHP`
 - [PassIt](https://passit.io/) - Simple password manage with sharing features by group and user, but no administration interface. ([Demo](https://app.passit.io/), [Source Code](https://gitlab.com/passit)) `AGPL-3.0` `Python`