start work on more mr config, add readme

README.md

@@ -11,6 +11,7 @@ This app will support the following subcommands:
 - mg pull
 - mg fetch
 - mg register
+- mg unregister
 
 Passing the `-jX` argument will spin up X jobs simultaneously
 
@@ -18,12 +19,14 @@ mg supports loading an existing ~/.mrconfig and migrating it to ~/.config/mg.con
 
 
 ## Improvements over mr:
-1. No external dependencies (except for git) 
+1. No external dependencies (even git!*) 
 1. More output options (summary of failures)
 1. More deterministic behavior (global vs local run)
 1. Exports public functions and can be embedded into other Go programs idiomatically
 
 
 ## Why to stick with mr:
-1. If you need support for non-git repos
+1. If you need support for non-git VCS tooling
 1. If you want to use the [mr plugin ecosystem](https://myrepos.branchable.com/#:~:text=repos%20to%20myrepos-,related%20software,-garden%3A%20manage%20git)
+
+*: custom-registered commands may rely on external applications.