message: Prague-Dump: Update usage in readme.md
diff: @@ -9,14 +9,19 @@ In order to connect to ODSP, the clientID and clientSecret must be set as enviro
  URL: <ODSP joinSession URL>|<Routerlicious URL>
  Options:
  --dump:rawmessage : dump all messages
  + --dump:snapshotVersion : dump a list of snapshot version
  --dump:snapshotTree : dump the snapshot trees
  --dump:snapshotBlob : dump the contents of snapshot blobs
  + --forceRefreshToken : Force refresh token (SPO only)
  --stat:message : show a table of message type counts and size
  --stat:snapshot : show a table of snapshot path and blob size
  --stat:dataType : show a table of data type
  --stat:channel : show a table of channel
  --filter:messageType <type> : filter message by <type>
  --jwt <token> : token to be used for routerlicious URLs
  + --numSnapshotVersions <number> : Number of versions to load (default:10)
  + --snapshotVersionIndex <number> : Index of the version to dump
  + --saveDir <outdir> : Save data of the snapshots and messages
  ## Example Output
  