My suggestion is to post small report updated like this every month, or at least every few months.
But how were you thinking I would do that?
Go listing the amounts donated and thank those who did (even if anonymously - I also don't know who made most of the donations, just those who informed here)?
Or just say, something like: this month I received x donations?
I think that listing all the addresses that you've received donations from would be a rather tedious process for you (and anyone is free to check the address using blockchair explorers).
However, I also agree with dkbit98 - It would be nice to have some information in the OP regarding the donations just to give an idea how financially capable is the project. What do you think of incorporating bitmover awesome API[1] to display the current balance of the donation address right in the OP? It would look something like this:
USD 
EUR 
This would ease some of your work since the balance would update automatically[1] (please correct me if I'm wrong bitmover) and users could directly see how donations are going. Plus, if you'd like, you could directly place this information right into the website which probably has more views than the thread, thus increasing its visibility.
Also, piggybacking on dkbit98 idea: Let's say that your monthly expenses are 100 and you currently have 800 of balance in the donation address. Then you currently surpassing the monthly expenses by 800% - this could also be inserted somewhere in the website so that users are aware of the financials. If instead you had only 50 of total donations then your % would just sit at 50%, signaling that the monthly expenses weren't covered.
[1]
https://bt.irlbtc.com/view/5452373.msg62238782#msg62238782