conf: Document libimcv options

conf/plugins/imc-test.opt

@@ -0,0 +1,14 @@
+charon.plugins.imc-test.additional_ids = 0
+	Number of additional IMC IDs.
+
+charon.plugins.imc-test.command = none
+	Command to be sent to the Test IMV.
+
+charon.plugins.imc-test.dummy_size = 0
+	Size of dummy attribute to be sent to the Test IMV (0 = disabled).
+
+charon.plugins.imc-test.retry = no
+	Do a handshake retry.
+
+charon.plugins.imc-test.retry_command =
+	Command to be sent to the Test IMV in the handshake retry.