what /_data/merchants.yml file used for?

nothing afaik. It should be just a leftover from an old merchant page

same for donators.yml, but was decided to keep it for the records

Then should I close this PR? monero-project/monero-site #2129

for monero-project/monero-site #2045 - my guess is trocador will have community support for being added (privacy aware service tor / no js etc). there are many other aggregators who want to be listed though (swapzone and orengefren listed in this PR) - i don't know about swapzone personally and orengefren is javascript only. i do know that stealthEx where trying to get listed (and appear as a sponsor on MoneroTalks

youtube channel) and im sure many of the others have done things im not aware of atm so this requires some discussion / thought