Sandpack June Update

Features

• Sandpack React: support add file method #512.

Bugs:

• Global-listeners on React package: doesn't unsubscribe all listeners on unsubscribe only one #516;
• Sandpack client: make template prop type-safe #504;
• Sandpack React: make sure the Sandpack context reacts to prop changes and recreate all states #498;
• Code-editor: improve the integration between the inline-error option and Codemirror #495;
• File-explorer: adds a property to not show hidden files #488;
• Theme: set color-scheme CSS property in theme context #491.

Others:

• Improve docs: update Nextjs example to use the latest API #515;
• Improve docs: make some common types public #494;
• Read-only and editor-state: improve the tests coverage #511;
• Chore: remove renderHiddenIframe which is no longer used #510.