Rule request: AvoidUsingBacktickLineTerminator

Summary of the new feature

As a code reviewer, I want script/module writers to receive automated informational warnings about backtick usage so that my review time isn't consumed by catching maintainability issues that tooling should prevent upfront.

Problem Statement:
The backtick (`) character is commonly used for line continuation in PowerShell, but it's considered poor practice for several reasons:

• Hard to see: Backticks are nearly invisible and easily missed during code review
• Poor readability: Makes code harder to read and understand
• Maintenance issues: Easy to accidentally remove or misplace during editing
• Non-intuitive: New PowerShell users often struggle with backtick usage

PowerShell offers better alternatives like parameter splatting and natural line breaks after operators/pipelines that are more readable and less error-prone.

Proposed technical implementation details

Rule Name: PSAvoidUsingBacktickLineTerminator

Severity: Information

Behavior:

• Flag any usage of backtick (`) character used for line continuation
• Suggest appropriate alternatives based on context

Recommended alternatives to suggest:

1. Parameter Splatting: For commands with multiple parameters
2. Natural line breaks: After pipeline operators (|), logical operators (-and, -or), comparison operators
3. Parentheses grouping: For complex expressions

Example violations:

# Backtick line continuation - Flagged
Get-Process -Name notepad `
    -ErrorAction SilentlyContinue `
    | Where-Object CPU -gt 100

# Complex command with backticks - Flagged  
$result = Get-ChildItem -Path C:\Temp `
    -Filter "*.txt" `
    -Recurse `
    -ErrorAction SilentlyContinue

Technical Implementation:

• I plan on taking this issue if approved.
• Simple class that inherits ITokenRule:

public IEnumerable<DiagnosticRecord> AnalyzeTokens(Token[] tokens, string fileName)
{
    if (tokens == null) throw new ArgumentNullException(Strings.NullTokensErrorMessage);

    var lineContinuationTokens = tokens.Where(token => token.Kind == TokenKind.LineContinuation);

    foreach (var tokenNode in lineContinuationTokens)
    {
        yield return new DiagnosticRecord(
            string.Format(CultureInfo.CurrentCulture, Strings.AvoidUsingBacktickLineTerminatorError),
            tokenNode.Extent,
            GetName(),
            DiagnosticSeverity.Information,
            fileName
        );
    }
}

What is the latest version of PSScriptAnalyzer at the point of writing

1.24.0

Start by examining existing ITokenRule implementations and the AnalyzeTokens entry point described in the issue, especially TokenKind.LineContinuation and the diagnostic message in Strings. Confirm how comparable rules are registered and tested. Done means backtick line-continuation tokens produce informational diagnostics with the rule name and source extent, without flagging unrelated tokens.