manifest.json — name
(a-z A-Z 0-9 _, max 128),
description (max 250), version_number
(Major.Minor.Patch),
dependencies (e.g. Team-Package-1.0.0),
website_url (or empty)
icon.png — exactly 256×256 pixels
README.md — UTF-8 markdown
CHANGELOG.md — optional
All names are case-sensitive and must be at the root of the ZIP
Updating a package
To release a new version, upload a new ZIP with the same
name and a higher
version_number. The README, changelog and icon are taken from the
newest ZIP.