Add new-markdown

[yunho0130]

Adding new-markdown — a one-click "New Markdown File" button for the macOS Finder toolbar.

What it does

• Click a Finder toolbar icon → creates a blank .md file in the front Finder window's folder
• Immediately enters rename mode so users can name and start typing
• No menu bar item, no dock icon, no background process

Why it fits this list

• Open source (Apache 2.0)
• Native macOS app (AppleScript bundle, no external runtime)
• Active maintenance (initial public release v1.0.0)
• Categories: finder + markdown (double-tagged for discoverability)
• Tested on macOS 13+ through macOS 26 (Tahoe)

Preview

Compliance with contribution guidelines

• ✅ Individual PR for a single suggestion
• ✅ Edits applications.json (not README.md)
• ✅ Follows the canonical entry schema
• ✅ Short, descriptive short_description ending in a period
• ✅ Categories are pre-existing IDs from categories.json
• ✅ Recent commits, README in English, has license