Update README.md

Author: zeng-github01

README.md

@@ -2,25 +2,68 @@
 A Unturned Rocket Plugin about CDKey. Support MySQL
 
 # Permssion
-Command:CDK Permission CDK
+**Command** | **Permission**
+---|---
+`cdk` | `cdk`
 
-# Database edit
-Give Items<br>
-Items id,id,id ----one by one<br>
-Amount number,number,number ---one by one<br> 
-<br>
-Example: <br>
-method 1 Items:253,253,253 => item 253x3<br>
+# Database editing
 
-method 2 Items:263. Amount:3 => item 253x3
+The database editing section describes the format of the data fields in the database.
 
-Give Permission<br>
+## Items and Amount fields
 
-GrantPermissionGroup:vip<br> 
-ValidUntil:use Navicat to modify it.It determines the validity period of the permission group<br>
-Tip1: Permission Group ID,NOT DisplayName<br>
-Tip2: Change "UsePermissionSync" to 1<br>
-It can let my another plugin "PermissionSync" to manager permission to give<br>
+The Items and Amount fields are used to store a list of items and their corresponding quantities.
 
-Change EnableRenew to 1.it can Enables CDK to be redeemed to extend the validity period of the permission group<br>
-ValidUntil needs to be modified synchronously to decide the extension time
+**Items field**
+
+When the Amount field is empty, the Items field must be a comma-separated list of ushort values, where each value represents an item id.
+
+**Examples**
+
+* When the Items field is `1,2,3` and the Amount field is ``, then the database stores a list of three items, each with a quantity of 1.
+* When the Items field is `1,2,3` and the Amount field is `1,2,3`, then the database stores a list of three items, where the first item has a quantity of 1, the second item has a quantity of 2, and the third item has a quantity of 3.
+
+**Notes**
+
+* The Items field is required.
+* The Amount field is optional.
+* When the Amount field is empty, the quantity for each item is assumed to be 1.
+
+**Additional notes:**
+
+* It is recommended to write both the Items and Amount fields together. This will make it easier to read and understand the data.
+
+
+# Permission group
+
+This document describes the format of the permission group data structure.
+
+
+The following fields are used to represent a permission group:
+
+* **GrantPermissionGroup:** The ID of the permission group.
+* **ValidUntil:** The expiration date of the permission group.
+* **EnableRenew:** Whether the permission group can be renewed.
+* **UsePermissionSync:** Whether the permission group management is delegated to another plugin.
+
+## Explanation
+
+* **GrantPermissionGroup:** The permission group ID is a unique string that identifies a permission group.
+* **ValidUntil:** The expiration date of a permission group is the date and time after which the permission group will be automatically revoked.
+* **EnableRenew:** When set to `1`, the permission group can be renewed. When set to `0`, the permission group cannot be renewed.
+* **UsePermissionSync:** When set to `1`, the permission group management is delegated to another plugin. When set to `0`, the permission group management is handled by this plugin.
+
+## Notes
+
+* **GrantPermissionGroup:** This is the ID of the permission group, **not** the display name.
+* **UsePermissionSync:** When set to `1`, the permission group management is delegated to another plugin. When set to `0`, the permission group management is handled by this plugin.
+* When `EnableRenew` is set to `1`, the `ValidUntil` field must also be set to a valid date and time.
+
+## CDK-related fields
+
+The following fields are used to represent CDK-related information about a key:
+
+* **CDKKey:** The CDK key used to redeem the permission group. This is the primary key.
+* **MaxRedeem:** The maximum number of times that this key can be redeemed.
+* **RedeemedTimes:** The number of times that this key has been redeemed.
+* **Owner:** The Steam digital ID of the owner of the key, if any.