Update doctype-first.mdx

[Esther22225]

Short description of what this resolves

Removes redundant examples and streamlines the documentation for the doctype-first rule. Helps clarify how the rule works and why it matters.

Proposed changes

• Removed duplicate examples of valid and invalid DOCTYPE placement
• Simplified the config section
• Preserved the explanation of why the rule is important

[gemini-code-assist]

Code Review

This pull request simplifies the documentation for the doctype-first rule by removing a redundant example. However, the change also removes a heading, which makes the remaining example lack context. I've added a suggestion to re-introduce the heading to maintain the document's clarity.

[gemini-code-assist]

While removing a redundant example is a good simplification, the removal of the heading ### The following patterns are **not** considered rule violations leaves this code block without context, making it unclear what the example demonstrates. To improve clarity, it's best to reintroduce a heading for this valid pattern example.

### The following patterns are **not** considered rule violations

```html

[Copilot]

Pull Request Overview

This PR streamlines the documentation for the doctype-first rule by removing redundant examples and simplifying the content structure. The changes focus on eliminating duplicate examples while preserving the essential rule explanation and importance.

• Removed duplicate valid DOCTYPE placement example
• Simplified documentation structure by removing unnecessary section headers
• Maintained the invalid example that demonstrates the rule violation

[Copilot]

After removing the valid example section, this code block appears to show an invalid pattern but lacks proper context. Consider adding a section header like '### The following patterns are considered rule violations:' before this example to clarify that this demonstrates what the rule flags as problematic.

[coliff]

thanks for the PR but the example you removed was important to show that a comment is valid before the doctype.