doc: redirect has been fixed (LedgerHQ#151)

LedgerHQ/developer-portal@6661ac7

Author: jnicoulaud-ledger

Diff for: README.md

@@ -1,6 +1,6 @@
 # ERC-7730 (Clear Signing Metadata) Registry
 
-The objective of ERC-7730 is to establish a standardized method for clear signing contracts and messages on EVM chains, by offering metadata formatting that complements ABIs and message types. To learn more about the ERC-7730 standard, visit [Ledger Developer Portal](https://developers.ledger.com/docs/clear-signing).
+The objective of ERC-7730 is to establish a standardized method for clear signing contracts and messages on EVM chains, by offering metadata formatting that complements ABIs and message types. To learn more about the ERC-7730 standard, visit [Ledger Developer Portal](https://developers.ledger.com/docs/clear-signing/erc7730).
 
 This repository maintains records of past and current metadata files in the `registry` directory.