Donation/support button

[asadsid95]

Re: #3

Description: Button for registered users shows on top bar, allowing payment to be made towards donation

Details:

• Use TailwindCSS and NextJS to create button
• Event listener for button click
• Modal/dialog box for entering donation info
• Validation and processing of donation data using NextJS -- which payment API to use? (Stripe?)
• Firebase to store data+metadata for user