Fix: Financial reports Grin address

[l33d4n]

Closes #406

[lehnberg]

Thanks for the PR!

Couple of things:

• 405 has now been merged, so Q4 could now be included

• From an auditing perspective, I'm not sure it's best that we blanket replace https://donations.grin-tech.org with grin1wm78wjsf2ws507hea4zqrcywxltjwhtgfrwzhdrr9l80l7tpz5fsj58lk0: We weren't up on slatepacks in the past, as it didn't exist, and funds were indeed received to grin-tech.org, even if we now no longer are in control of the domain. How about we instead `code comment` the URL out with backticks, and then move to the slatepack address from when we started using it, which I believe was in Q1 2021?