[Bug] Update Graduated Group members

[nsryan2]

Describe the bug.

Riley Fisher graduated from the group, and his profile on https://arfc.github.io/people/ should be moved to https://arfc.github.io/people/alumni .

Steps to reproduce the bug.

Steps to reproduce the behavior (ideally as a minimum example of where the failure is coming from with code blocks for error messages and inputs):

1. Visit the page linked above and scroll down to find Riley's profile.

What inputs and outputs are involved?

The source for the current people is in: https://github.com/arfc/arfc.github.io/blob/source/_data/people.yml

The source for alumni is in https://github.com/arfc/arfc.github.io/blob/source/_data/alumni.yml

Are there additional replication details?

• Operating System: n/a
• Software Version: n/a
• Python Version: n/a

What is the expected behavior?

We would expect that everyone who has graduated from the group is displayed on our alumni page. Ideally with a brief sentence about where they went next.

Additional context.

In Riley's case, I would suggest changing his blurb to read:
"""
Riley was an undergraduate in NPRE at UIUC where he studied the interactions between society, policy, and reactor technologies. Following graduation, Riley started his graduate studies at the University of Michigan Ann Arbor.
"""

How can this issue be closed?

This Issue can be closed with a PR that moves Riley's bio information from the current people page to the alumni page. This PR should also update his bio to be in the past tense.