Add verify credentials tutorial for Javascript

_code-samples/verify-credential/js/README.md

@@ -0,0 +1,30 @@
+# Verify Credential - Javascript sample code
+
+Verifies that a specific credential exists on the XRPL and is valid.
+
+Quick install & usage:
+
+```sh
+blob
+```
+
+`verify_credential.js` can also be used as a commandline utility. Full usage statement:
+
+```sh
+$ ./verify_credential.js -h
+usage: verify_credential.js [-h] [-b] [-n {devnet,testnet,mainnet}]
+                            [issuer] [subject] [credential_type]
+
+Verify an XRPL credential
+
+positional arguments:
+  issuer                Credential issuer address as base58.
+  subject               Credential subject (holder) address as base58.
+  credential_type       Credential type as string
+
+options:
+  -h, --help            show this help message and exit
+  -b, --binary          Use binary (hexadecimal) for credential_type
+  -n, --network {devnet,testnet,mainnet}
+                        Use the specified network for lookup
+```