Documentation polishing

[teon]

• Add information about dashboard page (from release 1.4)
• Update network overview
• Rewrite Desktop client to add all help (like on mobile)
• SSO (OpenID Connect) - add information that Defguard is an OIDC provider and can be a SSO system for other apps, also that we use internal Multi-Factor methods when conneting to a location with Internal MFA
• External OpenID providers - each should be visible in the menu
• Enterprise features - brakuje info ze External MFA dla lokalizacji od 1.5