Added sequence diagram

pq-tls-benchmark-framework/emulation-exp/code/kex/docs/Makefile

+
+sequence_diagram.pdf: sequence_diagram.puml
+	plantuml -tpdf $<

pq-tls-benchmark-framework/emulation-exp/code/kex/docs/sequence_diagram.puml

+@startuml sequence_diagram
+activate Client
+Client -> Client: do_tls_handshake()
+activate Client
+
+' activate NetEm
+' ' ||1||
+' deactivate NetEm
+
+Client -> Client: KeyGen()
+activate Client
+deactivate Client
+Client -> NetEm: { Client Hello }
+
+' Client -> Client: waiting for response
+' deactivate Client
+' ... Client waiting ...
+' deactivate Client
+
+activate NetEm
+NetEm -> Server: { Client Hello }
+' ... Server waiting ... 
+deactivate NetEm
+activate Server
+Server -> Server: generate_response()
+activate Server
+Server -> Server: Encaps()
+activate Server
+deactivate Server
+deactivate Server
+' Server -> NetEm: Server Hello, Encrypted Extensions, Certificate, Certificate Verify,Finished
+Server -> NetEm: { Server Hello, Certificate, Finished }
+deactivate Server
+
+activate NetEm
+NetEm -> Client: { Server Hello, Certificate, Finished }
+deactivate NetEm
+
+Client -> Client: Decaps()
+activate Client
+deactivate Client
+deactivate Client
+@enduml