chore: fix links for nonce and signed hash

EIPS/eip-5539.md

@@ -231,13 +231,13 @@ This section uses the following terms:
 - **`transaction signer`**: An Ethereum address that signs arbitrary data for the contract to execute **BUT** does not commit the transaction.
 - **`transaction sender`**: An Ethereum address that takes signed data from a **transaction signer** and commits it wrapped with its own signature to the smart contract.
 
-An address (**transaction signer**) **MAY** be able to deliver a signed payload off-band to another address (**transaction sender**) that initiates the Ethereum interaction with the smart contract. The signed payload **MUST** be limited to be used only once ([Signed Hash](#Signed-Hash) + [nonces](#Nonce)).
+An address (**transaction signer**) **MAY** be able to deliver a signed payload off-band to another address (**transaction sender**) that initiates the Ethereum interaction with the smart contract. The signed payload **MUST** be limited to be used only once ([Signed Hash](#SignedHash) + [nonces](#Nonce)).
 
-#### Signed Hash
+#### Signed Hash <span id="SignedHash"></span>
 
 The signature of the **transaction signer** **MUST** conform [EIP-712](./eip-712.md). This helps users understand what the payload they're signing consists of & it improves the protection against replay attacks.
 
-#### Nonce
+#### Nonce <span id="Nonce"></span>
 
 This EIP **RECOMMENDS** the use of a **dedicated nonce mapping** for meta transactions. If the signature of the **transaction sender** and its meta contents are verified, the contract increases a nonce for this **transaction signer**. This effectively removes the possibility for any other sender to execute the same transaction again with another wallet.