doc: document the use of "-vv" to display commands

doc/src/commands.md

@@ -484,6 +484,8 @@ garden or tree scope.
 For example, `garden build treesitters catsitters` will run a user-defined `build`
 command over both the `treesitters`  and `catsitters` groups.
 
+Use the `garden -vv` extra-verbose option to display the commands being run.
+
 
 ## garden exec
 
@@ -499,6 +501,8 @@ When the `<tree-query>` resolves to a garden then the environment
 is configured for the command using the environment variables and
 custom commands from both the tree and the garden.
 
+Use the `garden -vv` extra-verbose option to display the command being run.
+
 
 ## garden eval