Update cmd/src/main.go

Co-authored-by: Beyang Liu <[email protected]>

Author: uwedeportivo

cmd/src/main.go

@@ -37,7 +37,7 @@ The commands are:
 	actions         runs actions to generate patch sets (experimental)
 	campaigns       manages campaigns (experimental)
 	lsif            manages LSIF data
-    validate        validate a Sourcegraph instance
+    validate        validate a Sourcegraph instance (experimental)
 	version         display and compare the src-cli version against the recommended version for your instance
 
 Use "src [command] -h" for more information about a command.