feat(pdf): add configurable PDF export and improve print rendering

lang/en.json

@@ -366,6 +366,32 @@
     "editor.enablePage": "Enable Page",
     "editor.enablePageTitle": "Enable or disable the published page",
     "editor.extendedMarkdown": "Extended Markdown",
+    "editor.pdfPopupBlocked": "The PDF window was blocked by the browser.",
+    "editor.pdfExportFailed": "Could not prepare the PDF.",
+    "editor.a4Portrait": "A4 — Portrait",
+    "editor.a4Landscape": "A4 — Landscape",
+    "editor.a3Portrait": "A3 — Portrait",
+    "editor.a3Landscape": "A3 — Landscape",
+    "editor.a5Portrait": "A5 — Portrait",
+    "editor.letterPortrait": "Letter — Portrait",
+    "editor.letterLandscape": "Letter — Landscape",
+    "editor.exportPdf": "Export PDF",
+    "editor.generatePdf": "Generate PDF",
+    "editor.includeDocumentTitle": "Include document title",
+    "editor.margins": "Margins",
+    "editor.narrowMargin": "Narrow (8 mm)",
+    "editor.normalMargin": "Normal (12 mm)",
+    "editor.pageBreak": "Page break (PDF)",
+    "editor.pageBreakShortcut": "Page break (PDF) · Ctrl/Cmd+Enter",
+    "editor.pageFormat": "Page format",
+    "editor.pdfPageBreakHelp": "Use --- or Ctrl/Cmd+Enter to start a new PDF page.",
+    "editor.preservePdfColors": "Preserve colors and backgrounds",
+    "editor.pdfColorHelp": "Keeps syntax highlighting, alerts, quotes, highlights, table headers, and other colors in the PDF.",
+    "editor.pdfPrintHelp": "The browser print dialog will open. Choose Save as PDF.",
+    "editor.pdfGeneratedFooter": "Generated by RustPad",
+    "editor.presentation16x9": "16:9 — Presentation",
+    "editor.presentation4x3": "4:3 — Presentation",
+    "editor.wideMargin": "Wide (20 mm)",
     "editor.failedMermaid": "Failed to load Mermaid.",
     "editor.fileCount": "{count} files",
     "editor.font": "Font",