Merge pull request #5 from alisonjo315/patch-2

add terminus 3 install instructions

Author: uberhacker

README.md

@@ -27,12 +27,19 @@ This will update the autocomplete commands and should be executed after every ne
 Learn more about [Terminus](https://pantheon.io/docs/terminus/) and [Terminus Plugins](https://pantheon.io/docs/terminus/plugins/).
 
 ## Installation:
-For installation help, see [Manage Plugins](https://pantheon.io/docs/terminus/plugins/).
 
+To install this plugin using Terminus 3:
+```
+terminus self:plugin:install terminus-plugin-project/terminus-autocomplete-plugin
+```
+
+On older versions of Terminus:
 ```
 mkdir -p ~/.terminus/plugins
-composer create-project -d ~/.terminus/plugins terminus-plugin-project/terminus-autocomplete-plugin:~2
+composer create-project --no-dev -d ~/.terminus/plugins terminus-plugin-project/terminus-autocomplete-plugin
 ```
+For help installing, see [Manage Plugins](https://pantheon.io/docs/terminus/plugins/).
+
 
 ## Requirements: