Correct small typo from previous PR

README.md

@@ -144,7 +144,7 @@ You can use `existing-mnemonic --help` to see all arguments. Note that if there
 | Argument | Type | Description |
 | -------- | -------- | -------- |
 | `--validator_start_index` | Non-negative integer | The index of the first validator's keys you wish to generate. If this is your first time generating keys with this mnemonic, use 0. If you have generated keys using this mnemonic before, use the next index from which you want to start generating keys from (eg, if you've generated 4 keys before (keys #0, #1, #2, #3), then enter 4 here.|
-| `--num_validators`  | Non-negative integer | The number new of signing keys you want to generate. Note that the child key(s) are generated via the same master key. |
+| `--num_validators`  | Non-negative integer | The number of new signing keys you want to generate. Note that the child key(s) are generated via the same master key. |
 | `--folder` | String. Pointing to `./validator_keys` by default | The folder path for the keystore(s) and deposit(s) |
 | `--chain` | String. `mainnet` by default | The chain setting for the signing domain. |
 | `--eth1_withdrawal_address` | String. Eth1 address in hexadecimal encoded form | If this field is set and valid, the given Eth1 address will be used to create the withdrawal credentials. Otherwise, it will generate withdrawal credentials with the mnemonic-derived withdrawal public key in [EIP-2334 format](https://eips.ethereum.org/EIPS/eip-2334#eth2-specific-parameters). |