a better readme

Author: jambun

README.md

@@ -1,2 +1,35 @@
 # as_getty_barcodes
-An ArchivesSpace plugin that adds the ability to download DataMatrix barcodes for AO Ref IDs
+
+An ArchivesSpace plugin that adds the ability to download DataMatrix
+barcodes for Archival Object Ref IDs.
+
+Compatible with ArchivesSpace v3.2.0. It will likely be fine on any
+recent version, but only tested on v3.2.0.
+
+Developed by Hudson Molonglo for the J. Paul Getty Trust.
+
+
+## Installation
+
+No special installation instructions.
+No Gems. No database migrations. No overridden templates.
+
+
+## Description
+
+Adds a button to the Archival Object toolbar. When clicked a Datamatrix
+barcode is generated using the AO's Ref Id, and is downloaded as a PNG image.
+
+The name of the file is based on the AO's Component Unique Identifier (CUI)
+as follows:
+```
+  barcode_[CUI].png
+```
+
+## Dependencies
+
+This plugin uses two open source java libraries to generate barcodes:
+  - [barcode4j.jar](https://barcode4j.sourceforge.net/)
+  - [jai-imageio-core-1.4.0.jar](https://mvnrepository.com/artifact/com.github.jai-imageio/jai-imageio-core)
+
+These are bundled with the plugin.