npm uses GitHub Flavored Markdown

READMEs for npm packages on npmjs.com are now rendered using GitHub Flavored Markdown.

npmjs.com was using a custom markdown renderer not fully compatible with GitHub Flavored Markdown. This difference meant a README displayed on npmjs.com did not necessarily match the README displayed on GitHub. Aligning to use the GitHub Flavored Markdown renderer ensures that your README is rendered the same on both sites.

All newly published packages are now rendered with GitHub Flavored Markdown; packages previously published to npmjs.com will be re-rendered over time.