improve: Add Security contact to contracts (#951)

Author: nicholaspai

contracts/Universal_SpokePool.sol

@@ -13,6 +13,7 @@ import "./SpokePool.sol";
  * @dev This contract has one onlyOwner function to be used as an emergency fallback to execute a message to
  * this SpokePool in the case where the light-client is not functioning correctly. The owner is designed to be set
  * to a multisig contract on this chain.
+ * @custom:security-contact bugs@across.to
  */
 contract Universal_SpokePool is OwnableUpgradeable, SpokePool, CircleCCTPAdapter {
     /// @notice The data store contract that only the HubPool can write to. This spoke pool can only act on

contracts/chain-adapters/Universal_Adapter.sol

@@ -19,6 +19,7 @@ interface IOwnable {
  * @dev This contract can be redeployed to point to a new HubPoolStore if the data store gets corrupted and new data
  * can't get written to the store for some reason. The corresponding Universal_SpokePool contract will
  * also need to be redeployed to point to the new HubPoolStore.
+ * @custom:security-contact bugs@across.to
  */
 contract Universal_Adapter is AdapterInterface, CircleCCTPAdapter {
     /// @notice Contract that stores calldata to be relayed to L2 via storage proofs.

contracts/chain-adapters/utilities/HubPoolStore.sol

@@ -15,6 +15,7 @@ interface IHubPool {
  * @dev This contract DOES NOT prevent replay attacks of storage proofs on the L2 spoke pool if the
  * UniversalStorageProof_Adapters using this contract are mapped to spokepools with the same address on different
  * L2 chains. See comment in storeRelayAdminFunctionCalldata() for more details.
+ * @custom:security-contact bugs@across.to
  */
 contract HubPoolStore {
     error NotHubPool();