Merge pull request #1669 from bitcoincoretech/issue_1654

#1654 add link to Web UI in README

Author: junderw

README.md

@@ -30,6 +30,7 @@ Mistakes and bugs happen, but with your help in resolving and reporting [issues]
 ## Documentation
 Presently,  we do not have any formal documentation other than our [examples](#examples), please [ask for help](https://github.com/bitcoinjs/bitcoinjs-lib/issues/new) if our examples aren't enough to guide you.
 
+You can find a [Web UI](https://bitcoincore.tech/apps/bitcoinjs-ui/index.html) that covers most of the `psbt.ts`, `transaction.ts` and `p2*.ts` APIs [here](https://bitcoincore.tech/apps/bitcoinjs-ui/index.html).
 
 ## Installation
 ``` bash