Update README.md

Author: DotJoshJohnson

README.md

@@ -1,3 +1,5 @@
+:exclamation: **NOTE: This project is no longer being maintained!** :exclamation:
+
 # X12
 A simple ASC X12 parser for NodeJS. Created originally for the [TC Toolbox](https://github.com/TrueCommerce/vscode-tctoolbox) project.
 
@@ -25,4 +27,4 @@ results.forEach((result) => {
     // result.segment
     // result.element(.value)
 });
-```
+```