fix: copy

[jfdoming]

Notion ticket link

n/a, we noticed this while discussing handoff

Implementation description

• "Jump Math" -> "JUMP Math" (this matches how the name is stylized on their website and in their emails)
• Change wording of verification email, since it was blatantly inaccurate before

Steps to test

1. n/a

What should reviewers focus on?

• Are there improvements to copy?

Checklist

• My PR name is descriptive and in imperative tense
• My commit messages are descriptive and in imperative tense. My commits are atomic and trivial commits are squashed or fixup'd into non-trivial commits
• I have run the appropriate linter(s)
• I have requested a review from the PL, as well as other devs who have background knowledge on this PR or who will be building on top of this PR

[github-actions]

Visit the preview URL for this PR (updated for commit a0b27e9):

https://jump-math-staging--pr611-julian-minor-copy-fi-6toxb40q.web.app

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