Add MacMD Viewer to tools directory

_tools/macmd-viewer.md

@@ -0,0 +1,74 @@
+---
+title: MacMD Viewer
+category: "documents"
+description: "MacMD Viewer is a native macOS Markdown viewer with Mermaid diagram support, QuickLook extension, and syntax highlighting."
+icon: macmd-viewer.png
+website: https://macmdviewer.com
+syntax:
+  - id: headings
+    available: y
+  - id: paragraphs
+    available: y
+  - id: line-breaks
+    available: y
+  - id: bold
+    available: y
+  - id: italic
+    available: y
+  - id: blockquotes
+    available: y
+  - id: ordered-lists
+    available: y
+  - id: unordered-lists
+    available: y
+  - id: code
+    available: y
+  - id: horizontal-rules
+    available: y
+  - id: links
+    available: y
+  - id: images
+    available: y
+  - id: tables
+    available: y
+  - id: fenced-code-blocks
+    available: y
+  - id: syntax-highlighting
+    available: y
+    notes: "Supports 190+ languages via highlight.js."
+  - id: footnotes
+    available: n
+  - id: heading-ids
+    available: y
+    notes: "Automatically generated from heading text."
+  - id: definition-lists
+    available: n
+  - id: strikethrough
+    available: y
+  - id: task-lists
+    available: y
+  - id: emoji-cp
+    available: y
+  - id: emoji-sc
+    available: n
+  - id: highlight
+    available: n
+  - id: subscript
+    available: n
+  - id: superscript
+    available: n
+  - id: auto-url-linking
+    available: y
+  - id: disabling-auto-url
+    available: n
+  - id: html
+    available: y
+---
+
+[MacMD Viewer](https://macmdviewer.com) is a native macOS application for viewing Markdown files. Built with SwiftUI, it provides a fast, focused reading experience without the overhead of an editor. MacMD Viewer is designed for people who write Markdown in their editor of choice and want a dedicated, reliable way to preview the rendered output.
+
+MacMD Viewer includes a QuickLook extension, so you can preview Markdown files directly in Finder by pressing the spacebar. It also ships with built-in Mermaid diagram rendering, making it a good fit for technical documentation that includes flowcharts, sequence diagrams, and other visualizations. Syntax highlighting covers 190+ programming languages via highlight.js.
+
+The application features a table of contents sidebar that highlights the active heading as you scroll, file watching for live updates when the source file changes, and a clean, distraction-free interface. MacMD Viewer is available as a one-time purchase for $19.99.
+
+{% include tool-syntax-table.html %}