Create [PageHeader] component

[poroia]

This component will act as a header for the Explore, World, and Module pages and would need to be created to properly adjust to each page.
It is in progress/finished by Daniel Kim on Slack. If you would like to work on this, please contact him.

• You would probably need to utilize the AvatarGroup under src/components/shared/high to create the avatars. See an example usage under src/components/Student/Dashboard/Journey/Floating.js. This component requires names for the AvatarGroup which may not have been built yet. See Modify [AvatarGroup] to display Names #19.
• Use the reusable button from src/components/shared/low for the action button.
• For the Last Commit part next to the star, consider using IconLine under src/components/shared/low

The component is under the Explore, World, and Module pages under Student View on the Figma.

For now, place this component under src/components/shared/high

This component can be directly created in the Activity component, which is under src/components/Activity/Activity. As shown in App.js, this component/view can be accessed by typing in the url: /activities/:id where :id is equal to any number

[mzp0625]

pull request: #28