message: README: add section on getting a summary from Mesh
  updates
diff: @@ -28,6 +28,34 @@ $ LD_PRELOAD=libmesh.so git status
  Please open an issue if you have questions (or issues)!
  +But will it blend?
  +------------------
  +
  +If you run a program linked against mesh (or with Mesh `LD_PRELOAD`ed), setting the variable `MALLOCSTATS=1` will instruct mesh to print a summary at exit:
  +
  +```
  +$ MALLOCSTATS=1 ./bin/redis-server-mesh ./redis.conf
  +25216:C 11 Mar 20:27:12.050 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
  +25216:C 11 Mar 20:27:12.050 # Redis version=4.0.2, bits=64, commit=dfe0d212, modified=0, pid=25216, just started
  +25216:C 11 Mar 20:27:12.050 # Configuration loaded
  +[...]
  +^C25216:signal-handler (1583983641) Received SIGINT scheduling shutdown...
  +25216:M 11 Mar 20:27:21.945 # User requested shutdown...
  +25216:M 11 Mar 20:27:21.945 * Removing the pid file.
  +25216:M 11 Mar 20:27:21.945 * Removing the unix socket file.
  +25216:M 11 Mar 20:27:21.945 # Redis is now ready to exit, bye bye...
  +MESH COUNT: 25918
  +Meshed MB (total): 101.2
  +Meshed pages HWM: 25918
  +Meshed MB HWM: 101.2
  +MH Alloc Count: 56775
  +MH Free Count: 17
  +MH High Water Mark: 82687
  +```
  +
  +Not all workloads experience fragmentation, so its possible that Mesh will have a small 'Meshed MB (total' number!
  +
  +
  Implementation Overview
  -----------------------
  