Issue with boolean switch after verb

**Issue**
When using a boolean switch after a verb, I cannot set it to false

**Example:**
app.exe install --feature=false

**Options class**

```
[Verb("install", HelpText = "Install something")]
class Options
{
[Option('f', "feature", Required = false, Default = true, HelpText = "Enable a feature")]
public bool EnableFeature { get; set; }
}
```

**Expected:**
Feature = False

**Actual result:**
Feature = True

**Demo code:**
[https://dotnetfiddle.net/lSBqxp](https://dotnetfiddle.net/lSBqxp)

**Edit1**
Add Options class code

先使用 `app.exe install --feature=false` 執行 issue 中連結的示範程式碼，並將回報的值與預期結果進行比較。追蹤 `install` 動詞和 `EnableFeature` 的布林選項處理；完成的標準是保留明確指定的 `false` 值，而不是將其替換為預設的 `true`。

由索引模型根據 Issue 內容生成。