Add more information to the README

plugins/getgb/README.md

-# *gb* plugin
+# `gb` plugin
 
-- aims to support completion for all *gb* commands
-- also supports completion for *gb* plugins such as *vendor*
+> A project based build tool for the Go programming language.
 
-See http://getgb.io for the full *gb* documentation
+See https://getgb.io for the full `gb` documentation
+
+* * * *
+
+- Adds completion support for all `gb` commands.
+- Also supports completion for the [`gb-vendor` plugin](https://godoc.org/github.com/constabulary/gb/cmd/gb-vendor).
+
+To use it, add `getgb` to your plugins array:
+```sh
+plugins=(... getgb)
+```
 
 ## Caveats
 
-- The *git* plugin installs an alias *gb* that usually conflicts with the *gb* program
+The `git` plugin defines an alias `gb` that usually conflicts with the `gb` program.
+If you're having trouble with it, remove it by adding `unalias gb` at the end of your
+zshrc file.