Readme: link to web version

Author: bbbbbr

README.md

@@ -1,3 +1,7 @@
+### Web Version
+A web build that runs in the browser is avaialble at:
+- https://bbbbbr.github.io/romusage/
+
 ### Note about GBDK-2020
 Note: This utility is now included in [GBDK-2020](https://github.com/gbdk-2020/gbdk-2020) (version 4.3.0+), so you may already have a copy if you're using that dev kit.