Added unsupported features for C# Client doc.
Added unsupported features for C# Client doc.

Donnerbart/hazelcast,emre-aydin/hazelcast,emre-aydin/hazelcast,emrahkocaman/hazelcast,tkountis/hazelcast,juanavelez/hazelcast,dbrimley/hazelcast,Donnerbart/hazelcast,Donnerbart/hazelcast,emrahkocaman/hazelcast,dbrimley/hazelcast,dsukhoroslov/hazelcast,mdogan/hazelcast,tufangorel/hazelcast,lmjacksoniii/hazelcast,lmjacksoniii/hazelcast,juanavelez/hazelcast,tombujok/hazelcast,mesutcelik/hazelcast,emre-aydin/hazelcast,dbrimley/hazelcast,tufangorel/hazelcast,mesutcelik/hazelcast,tombujok/hazelcast,tufangorel/hazelcast,dsukhoroslov/hazelcast,tkountis/hazelcast,mesutcelik/hazelcast,mdogan/hazelcast,tkountis/hazelcast,mdogan/hazelcast