docs: improve the hot reload section, add run command example (#13418)

doc/docs.md

@@ -5590,6 +5590,12 @@ fn main() {
 ```
 
 Build this example with `v -live message.v`.
+	
+You can also run this example with `v -live run message.v`. 
+	Make sure that in command you use a path to a V's file, 
+	**not** a path to a folder (like `v -live run .`) - 
+	in that case you need to modify content of a folder (add new file, for example), 
+	because changes in *message.v* will have no effect.
 
 Functions that you want to be reloaded must have `[live]` attribute
 before their definition.