[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

docs.cloudstack.apache.org/en/latest/adminguide/usage.html#usage-types の使用タイプのセクションから始め、list usagetypes のレスポンスおよび UsageTypes.java と比較します。ドキュメントを更新して、記載されている使用タイプが25個の API エントリと一致するようにし、その後、レンダリングされたセクションが完全かつ正確であることを確認します。

索引モデルが issue の本文から書いたものです。