Improve Identity Providers Documentation and Navigation under Self-Hosted (#501)

* Refactor NavigationDocs component and update documentation structure - Improved formatting and organization of the NavigationDocs component for better readability. - Updated the docsNavigation structure to include detailed sections for managing peers, access control, networks, and integrations. - Removed the identity providers documentation file as part of the restructuring effort. - Enhanced the overall navigation experience by ensuring all links are properly formatted and accessible. * Update NavigationDocs to include new SSO links and remove outdated documentation - Added links for Authentik, Keycloak, Auth0, and JumpCloud under the Single Sign-On section in NavigationDocs. - Removed the single-sign-on.mdx file as part of the documentation cleanup effort. * Add more info about self-hosted IdP support * Update Single Sign-On documentation and NavigationDocs - Updated titles and added introductory text for Auth0, Authentik, JumpCloud, and Keycloak pages to clarify their use as Identity Providers with NetBird. - Commented out the links section in NavigationDocs for Single Sign-On to reflect the current documentation state. Didn't make sense to have those and didn't want to confuse people thinking those are the only supported providers. - Enhanced the index page to include detailed descriptions and setup buttons for Okta ans each OIDC Identity Provider. * Update paths in structure and documentation for Auth0, Authentik, Keycloak, Microsoft Entra ID, Google Workspace, and JumpCloud. This cleanup enhances clarity and ensures all references point to the correct resources. --------- Co-authored-by: braginini <bangvalo@gmail.com>

Author: TechHutTV