feat: implement cmd_duration for bash (#144)

docs/config/README.md

@@ -119,11 +119,16 @@ The `cmd_duration` module shows how long the last command took to execute.
 The module will be shown only if the command took longer than two seconds, or
 the `min_time` config value, if it exists.
 
-::: warning NOTE
-Command duration is currently not supported in `bash`. See
-[this issue](https://github.com/starship/starship/issues/124) for more details.
+::: warning Do Not Hook the DEBUG trap in Bash
+If you are running Starship in `bash`, do not hook the `DEBUG` trap after running
+`eval $(starship init $0)`, or this module **will** break.
 :::
 
+Bash users who need preexec-like functionality can use
+[rcaloras's bash_preexec framework](https://github.com/rcaloras/bash-preexec).
+Simply define the arrays `preexec_functions` and `precmd_functions` before 
+running `eval $(starship init $0)`, and then proceed as normal.
+
 ### Options
 
 | Variable   | Default | Description                         |