Improve rule suppression documentation

Existing documentation doesn't provide any information regarding rule-wise behavior of code suppression.

For example, PSSA cannot suppress PSAvoidUsingUserNameAndPassWordParams violations based on given rulesuppressionid.

    Configuration Foo
    {             
     [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSAvoidUsingUserNameAndPassWordParams", "UserName", Scope="Function")]
     [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSAvoidUsingUserNameAndPassWordPara", "EncryptedPassword", Scope="Function")]
        param (
            [Parameter(Mandatory)]
            [String]$UserName,

            [Parameter(Mandatory)]
            [String]$Password
        )

    }

該 issue 沒有指定文件檔案或測試。首先找到現有的規則抑制文件，並檢查 PSSA 如何處理所示的 SuppressMessageAttribute 範例，包括 rulesuppressionid 值。完成的標準是：文件說明依規則進行抑制的行為，並涵蓋 PSavoidUsingUserNameAndPassWordParams 範例。