Custom Elements Manifest Analyzer Plugins

• cem-plugin-async-function Add async flag to functions
• cem-plugin-copy Copy files after analyzing
• cem-plugin-jsdoc-example Handle @example JSDoc
• cem-plugin-module-file-extensions Rename file extensions
• cem-plugin-readonly Add readonly flag to class memebers
• cem-plugin-type-descriptions-markdown Append Markdown to class member, parameter, and return type descriptions