Convert the "Metadata" collapsible panel to React, using Bootstrap collapse (http://v4-alpha.getbootstrap.com/components/collapse/). Note that keyboard accessibility is important, and if possible we should try to avoid recreating this UI component form scratch (even if its simple).
This will be the first time we're using a React component in the entwine-powered CMS Pages edit form, so you'll likely need a bit of help from an Open Sourcerer to create an entwine wrapper that instanciates the React component.
Convert the "Metadata" collapsible panel to React, using Bootstrap collapse (http://v4-alpha.getbootstrap.com/components/collapse/). Note that keyboard accessibility is important, and if possible we should try to avoid recreating this UI component form scratch (even if its simple).
Might take some inspiration from react-bootstrap (https://github.com/react-bootstrap/react-bootstrap/blob/master/src/Collapse.js) - the library is not compatible with Bootstrap 4 yet, so we can't use the components outright.
Adjust the styling to a flatter look, taking inspiration from the guidelines at https://projects.invisionapp.com/boards/9GX68PTXUQFH/
This will be the first time we're using a React component in the entwine-powered CMS Pages edit form, so you'll likely need a bit of help from an Open Sourcerer to create an entwine wrapper that instanciates the React component.
We don't have good docs on React component use yet, check https://github.com/Automattic/wp-calypso/blob/master/docs/components.md and https://github.com/Automattic/wp-calypso/blob/master/docs/coding-guidelines/css.md