Fix spelling and grammar in comments (#3408)

(cherry picked from commit e633ee9ed3fe45290fb02cdc61eaac3c82b6ba76)

contracts/proxy/ERC1967/ERC1967Proxy.sol

@@ -17,7 +17,7 @@ contract ERC1967Proxy is Proxy, ERC1967Upgrade {
      * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
      *
      * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
-     * function call, and allows initializating the storage of the proxy like a Solidity constructor.
+     * function call, and allows initializing the storage of the proxy like a Solidity constructor.
      */
     constructor(address _logic, bytes memory _data) payable {
         assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));

contracts/proxy/beacon/BeaconProxy.sol

@@ -8,7 +8,7 @@ import "../Proxy.sol";
 import "../ERC1967/ERC1967Upgrade.sol";
 
 /**
- * @dev This contract implements a proxy that gets the implementation address for each call from a {UpgradeableBeacon}.
+ * @dev This contract implements a proxy that gets the implementation address for each call from an {UpgradeableBeacon}.
  *
  * The beacon address is stored in storage slot `uint256(keccak256('eip1967.proxy.beacon')) - 1`, so that it doesn't
  * conflict with the storage layout of the implementation behind the proxy.
@@ -20,7 +20,7 @@ contract BeaconProxy is Proxy, ERC1967Upgrade {
      * @dev Initializes the proxy with `beacon`.
      *
      * If `data` is nonempty, it's used as data in a delegate call to the implementation returned by the beacon. This
-     * will typically be an encoded function call, and allows initializating the storage of the proxy like a Solidity
+     * will typically be an encoded function call, and allows initializing the storage of the proxy like a Solidity
      * constructor.
      *
      * Requirements:

contracts/security/PullPayment.sol

@@ -44,7 +44,7 @@ abstract contract PullPayment {
      *
      * @param payee Whose payments will be withdrawn.
      *
-     * Causes the `escrow` to emits a {Withdrawn} event.
+     * Causes the `escrow` to emit a {Withdrawn} event.
      */
     function withdrawPayments(address payable payee) public virtual {
         _escrow.withdraw(payee);
@@ -66,7 +66,7 @@ abstract contract PullPayment {
      * @param dest The destination address of the funds.
      * @param amount The amount to transfer.
      *
-     * Causes the `escrow` to emits a {Deposited} event.
+     * Causes the `escrow` to emit a {Deposited} event.
      */
     function _asyncTransfer(address dest, uint256 amount) internal virtual {
         _escrow.deposit{value: amount}(dest);

contracts/token/ERC1155/ERC1155.sol

@@ -394,7 +394,7 @@ contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI {
     /**
      * @dev Approve `operator` to operate on all of `owner` tokens
      *
-     * Emits a {ApprovalForAll} event.
+     * Emits an {ApprovalForAll} event.
      */
     function _setApprovalForAll(
         address owner,

contracts/token/ERC721/ERC721.sol

@@ -353,7 +353,7 @@ contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
     /**
      * @dev Approve `to` to operate on `tokenId`
      *
-     * Emits a {Approval} event.
+     * Emits an {Approval} event.
      */
     function _approve(address to, uint256 tokenId) internal virtual {
         _tokenApprovals[tokenId] = to;
@@ -363,7 +363,7 @@ contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
     /**
      * @dev Approve `operator` to operate on all of `owner` tokens
      *
-     * Emits a {ApprovalForAll} event.
+     * Emits an {ApprovalForAll} event.
      */
     function _setApprovalForAll(
         address owner,