changes to commands

README.md

@@ -5,12 +5,30 @@
 
 ## Commands
 
-asdf package install <package> <version>
-asdf package uninstall  <package> <version>
-asdf package installed <package>
-asdf package available <package>
-asdf package use <package> <version>
+asdf install <package> <version>
+asdf uninstall <package> <version>
+asdf installed <package>
+asdf available <package>
+asdf use <package> <version>
 asdf source add <package> <source>
 asdf source remove <package>
 asdf source update --all
 asdf source update <package>
+
+## `.asdf-versions` file
+
+```
+elixir 1.0.0
+erlang 17.3
+```
+
+
+## Package source structure
+
+A package source is a git repo, with the following files
+
+* `bin/install`
+* `bin/uninstall`
+* `bin/use`
+
+These scripts are run when `package install`, `package uninstall` or `package use` commands are run. You can set or unset env vars,