* add validation for blog plugin
* fix wrong default component
* fix test and add yup to package.json
* remove console.log
* add validation for classic theme and code block theme
* add yup to packages
* remove console.log
* fix build
* fix logo required
* replaced yup with joi
* fix test
* remove hapi from docusuars core
* replace joi with @hapi/joi
* fix eslint
* fix remark plugin type
* change remark plugin validation to match documentation
* move schema to it's own file
* allow unknown only on outer theme object
* fix type for schema type
* fix yarn.lock
* support both commonjs and ES modules
* add docs for new lifecycle method
* More prep
* rename xxx-api to api-xxx
* move content around for plugins and themes
* wip docs: using themes
* docs(v2): tweak using plugins
* docs(v2): list official themes in docs
* docs(v2): advanced themes
* wip notes for lifecycle apis
* resolve PR review discussions
* lower case "theme"
* better intro for using themes
* add a simple README to @docusaurus/theme-classic
* remove list of components from theme classic README and replace with link to directory