Upon Stripe donation, redirect to an active TCL page

[stacietaylorcima]

Summary

Donations redirect to /about-us?donation=success#donation, which no longer exists. The redirect should, instead, point to /?donation=success#donation

Relevant context

From Slack:

I just donated and it redirects to https://the-collab-lab.codes/about-us?donation=success#donation which no longer exists and there is no redirect set up.

Acceptance criteria

• Donating redirects to /?donation=success#donation
• A toast element appears at the top of the window, confirming to the user that the donation was successful