remove aliases to generic topics

Convert them to related topics instead.

It was confusing to click on the `identity` topic used on an internal company repository to see it with a description for a commercial identity platform.

Author: Samuel Parkinson

topics/auth0/index.md

@@ -1,10 +1,9 @@
 ---
-aliases: identity, id-as-a-service, idaas
 created_by: Eugenio Pace and Matías Woloski
 display_name: Auth0
 github_url: https://github.com/Auth0
 logo: auth0.png
-related: single-sign-on, token-based-authentication, json-web-token, openid-connect, oauth, ws-federation, saml, identity-providers, sdk, enterprise-integration 
+related: single-sign-on, token-based-authentication, json-web-token, openid-connect, oauth, ws-federation, saml, identity, idaas, id-as-a-service, identity-providers, sdk, enterprise-integration 
 released: 2013
 short_description: Auth0 is an Identity-as-a-Service provider. 
 topic: auth0