daemon: Added a ShortDescription

cmd/ipfs2/daemon.go

@@ -16,7 +16,14 @@ import (
 
 var daemonCmd = &cmds.Command{
 	Helptext: cmds.HelpText{
-		Tagline: "run a network-connected ipfs node", // TODO adjust copy
+		Tagline: "Run a network-connected IPFS node",
+		ShortDescription: `
+'ipfs daemon' runs a persistent IPFS daemon that can serve commands
+over the network. Most applications that use IPFS will do so by
+communicating with a daemon over the HTTP API. While the daemon is
+running, calls to 'ipfs' commands will be sent over the network to
+the daemon.
+`,
 	},
 
 	Options:     []cmds.Option{},