v1.3.8

What's Changed

• 🤖 Add flake.nix for Nix users by @agoose77 in #1509
• 👷 Check platform.system to fix myst on Windows by @agoose77 in #1510
• 🔬 Improve documentation for kernel spec and cell blocks by @ValMystletainn in #1507
• 📦 Use nodeenv when Node.js can't be found by Python package by @agoose77 in #1487
• 🚧 Fix overzealous warning about missing kernelspec by @agoose77 in #1513
• 🐛 Ensure that AMS Math environments are fully enclosed. by @rowanc1 in #1520
• 🐞 Directive option flag is always a boolean by @rowanc1 in #1517
• 🃏 Add card documentation and alias to link/url by @rowanc1 in #1521

Full Changelog: https://github.com/jupyter-book/mystmd/compare/[email protected]@1.3.8