updated README

README.md

@@ -16,7 +16,31 @@ cp mortadelo /usr/local/bin/
 
 ### How to use it
 
-You can use explicit arn roles or use a _role alias_ configured in `~/.mortadelo/roles`
+```
+Usage:
+  mortadelo [OPTIONS] <assume | clean | configure>
+
+Help Options:
+  -h, --help  Show this help message
+
+Available commands:
+  assume     assume role
+  clean      clean generated files
+  configure  configure roles alias file
+```
+
+**Using an explicit arn role:**
+
+`mortadelo assume -r arn:aws:iam::xxxxxxxxxxxx:role/foo -s foo`
+
+**Using an alias for a role configured in a file (~/.mortadelo/roles by default)**
+
+`mortadelo assume -a bar`
+
+**Configuring a new roles alias file (~/.mortadelo/roles by default):**
+
+`mortadelo configure -a bar`-r arn:aws:iam::xxxxxxxxxxxx:role/bar`
+
 
 **Roles file example**