Add usage and update TODO

README.md

@@ -3,8 +3,36 @@ ff is a command-line tool to manage favorite folders, creating an alias, to be u
 
 [![asciicast](https://asciinema.org/a/UCxUx5TkKEUEitKyg8FEUZFCi.svg)](https://asciinema.org/a/UCxUx5TkKEUEitKyg8FEUZFCi)
 
+# Usage
+
+```bash
+$ ff
+ff is a command-line tool to manage favorite folders, creating an alias,
+to be used via shell directly with the cd command.
+
+Usage:
+  ff [command]
+
+Available Commands:
+  add         Create a directory alias
+  alias       Prints out the path to the alias file.
+  delete      Delete a directory alias.
+  get         Return the raw path of an alias.
+  help        Help about any command
+  list        List saved aliases.
+  panic       WARINING!! This delete all saved data
+  update      Update a directory alias
+
+Flags:
+  -h, --help      help for ff
+  -v, --version   version for ff
+
+Use "ff [command] --help" for more information about a command.
+```
+
 # TODO
 - [ ] clean up the code
 - [X] use github workflow to build the binary
+- [ ] use github.com/manifoldco/promptui for edit command
 - [ ] make a better readme
 - [ ] ......