Add profile picture for Raphina Liu

[sofiabobadilla]

Adds img/people/raphina.jpeg (200x200, 9.8 KB) and the matching image: key in _data/people.yml, so the People page renders the photo instead of the initials placeholder.

The image is already square, so it drops straight into the 70px circle with no cropping needed.

Note on #8

This branches off master, so it keeps Raphina's current role: engineer. #8 changes that same entry to role: grad — whichever merges second may need a small conflict resolution on those adjacent lines. The intended end state is both: role: grad and the image: key.

Test plan

Verified with a local jekyll serve: the entry renders as <img class="rounded-circle profile"> and the image serves 200.

🤖 Generated with Claude Code

[monperrus]

@copilot resolve the merge conflicts in this pull request please make no mistake

[Copilot]

@copilot resolve the merge conflicts in this pull request please make no mistake

Done. Merged master into this branch and resolved the conflict in _data/people.yml by keeping both role: grad (from #8) and image: "/img/people/raphina.jpeg" (from this PR). Merge commit: d8acf88.