Add Heroes members page

Adding page to display our Heroes members as a way to give them recognition and express our appreciation and pride for their participation.

MR includes:

• Addition of Heroes members page with 3 Core team members who applied for the program
• Addition of documentation so future Heroes can add themselves to the page
• Addition of a link to the new Heroes members page from the Heroes program page
• Creation of a new heroes.yml file which populates the page