Add blockquote conversion support to vscode-to-beehiiv tool

[rodrigogiraoserrao]

Motivation

• Convert Markdown blockquotes into Beehiiv-compatible blockquote figures so the VS Code → Beehiiv workflow preserves quoted content correctly.

Description

• Add a BLOCKQUOTE_STYLE constant and a BLOCKQUOTE handling branch inside convertMarkdownToBeehiiv in vscode-to-beehiiv.html.
• Emit a <figure data-variant="2" data-type="blockquoteFigure"> wrapper containing a <blockquote> with one or more <p data-id=...> paragraphs.
• Preserve inline HTML and formatting in quote paragraphs and run the same link (target, rel, class) and code language normalization as other blocks.
• Handle blockquotes that contain no <p> by creating a paragraph from the blockquote text.

Testing

• Served the tool with python3 -m http.server 4173 --directory /workspace/tools and validated the UI loaded successfully.
• Ran a Playwright script that filled #markdown-input with > You probably could have guessed that command and confirmed the generated HTML contains a <figure ... data-type="blockquoteFigure"> block (succeeded).
• Captured a screenshot of the rendered preview to verify visual output (succeeded).

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Codex Task