docs(settings): clarify non-OIDC login methods

Updates the user settings documentation to be more generic. Instead of stating users can only sign
in with their email address, the text now correctly states that they can use their username or email
address. This accounts for both local and media server users.

Addresses seerr-team#1505 (comment)

Author: psavarmattas

docs/using-jellyseerr/settings/users/index.md

@@ -26,7 +26,7 @@ This setting is **enabled** by default.
 
 When enabled, users will be able to sign in to Jellyseerr using their OpenID Connect credentials, provided they have linked their OpenID Connect accounts. Once enabled, the [OpenID Connect settings](./oidc.md) can be accessed using the settings cog to the right of this option, and OpenID Connect providers can be configured.
 
-When disabled, users will only be able to sign in using their email address. Users without a password set will not be able to sign in to Jellyseerr.
+When disabled, users will only be able to sign in using their Jellyseerr username or email address. Users without a password set will not be able to sign in to Jellyseerr.
 
 This setting is **disabled** by default.