DOCSP-48416 add network compression FAQ (#738)

* DOCSP-48416 add network compression FAQ

* changes link to use the option rather than config file reference

* Add context to link

Author: jwilson-mdb

source/faq.txt

@@ -144,6 +144,21 @@ error:
 ``mongosync`` accepts all other :ref:`connection string options
 <mongodb-uri>`.
 
+Does ``mongosync`` support network compression?
+-----------------------------------------------
+
+``mongosync`` supports network compression. To enable network compression,
+your configuration must meet the following criteria:
+
+- Your source and destination clusters must have network compression enabled
+- Your source and destination cluster connection strings must include the 
+  :urioption:`compressors` connection string option
+- Your cluster configurations and connection string options must share at least 
+  one common compressor
+
+For more information about network compression configuration options, see the 
+:option:`--networkMessageCompressors <mongos --networkMessageCompressors>` option
+in the Database Manual.
 
 Which security and authentication options are supported?
 --------------------------------------------------------