[Doc] Usage Types update

### problem

Usage types in the docs is not in sync with the list usagetypes API response / code.

Check / Update the usage types in the doc here: https://docs.cloudstack.apache.org/en/latest/adminguide/usage.html#usage-types.

list usagetypes API response =>
```
(usageenv) 🐱 > list usagetypes
{
"count": 25,
"usagetype": [
{
"description": "Running Vm Usage",
"usagetypeid": 1
},
{
"description": "Allocated Vm Usage",
"usagetypeid": 2
},
{
"description": "IP Address Usage",
"usagetypeid": 3
},
{
"description": "Network Usage (Bytes Sent)",
"usagetypeid": 4
},
{
"description": "Network Usage (Bytes Received)",
"usagetypeid": 5
},
{
"description": "Volume Usage",
"usagetypeid": 6
},
{
"description": "Template Usage",
"usagetypeid": 7
},
{
"description": "ISO Usage",
"usagetypeid": 8
},
{
"description": "Snapshot Usage",
"usagetypeid": 9
},
{
"description": "Security Group Usage",
"usagetypeid": 10
},
{
"description": "Load Balancer Usage",
"usagetypeid": 11
},
{
"description": "Port Forwarding Usage",
"usagetypeid": 12
},
{
"description": "Network Offering Usage",
"usagetypeid": 13
},
{
"description": "VPN users usage",
"usagetypeid": 14
},
{
"description": "VM Disk usage(I/O Read)",
"usagetypeid": 21
},
{
"description": "VM Disk usage(I/O Write)",
"usagetypeid": 22
},
{
"description": "VM Disk usage(Bytes Read)",
"usagetypeid": 23
},
{
"description": "VM Disk usage(Bytes Write)",
"usagetypeid": 24
},
{
"description": "VM Snapshot storage usage",
"usagetypeid": 25
},
{
"description": "Volume on secondary storage usage",
"usagetypeid": 26
},
{
"description": "VM Snapshot on primary storage usage",
"usagetypeid": 27
},
{
"description": "Backup storage usage",
"usagetypeid": 28
},
{
"description": "Bucket storage usage",
"usagetypeid": 29
},
{
"description": "Network usage",
"usagetypeid": 30
},
{
"description": "VPC usage",
"usagetypeid": 31
}
]
}
(usageenv) 🐱 >
```

https://github.com/apache/cloudstack/blob/39c5641cbe674b19bc77082b850565f634a7cb84/api/src/main/java/org/apache/cloudstack/usage/UsageTypes.java#L24-L50

### versions

4.19.1 / 4.20.0

从 docs.cloudstack.apache.org/en/latest/adminguide/usage.html#usage-types 的使用类型部分开始，并将其与 list usagetypes 响应和 UsageTypes.java 进行比较。更新文档，使列出的使用类型与 25 个 API 条目一致，然后验证渲染后的部分是否完整且准确。

由索引模型根据 Issue 内容生成。