FAQ added expiration of membership

https://gitlab.ics.muni.cz/cloud/internal-wiki/-/issues/186

faq/README.md

@@ -48,6 +48,11 @@ To access internet from an instance, or access instance from the internet, you c
 
 In case, that these options are not suitable for you usecase, you can still request multiple floating IPs.
 
+## I can't log into openstack, how is that possible ?
+The most common reason why you can't log into your openstack account is because your membership in Metacentrum has expired. To extend your membership in Metacentrum,
+you can visit [https://metavo.metacentrum.cz/en/myaccount/prodlouzeni](https://metavo.metacentrum.cz/en/myaccount/prodlouzeni).
+
+
 ## PuTTY
 [PuTTY](https://www.chiark.greenend.org.uk/~sgtatham/putty/faq.html#faq-what) is a client program for the SSH on Windows OS.