Someone in the United States Congress edited The Legend of Zelda wikipedia page so that all mentions of the game's protagonist Link was replaced by Zelda, the princess for which the game series is named after but definitely not the playable main character of the series (yet).
@congressedits is a Twitter bot that tweets anonymous edits made to Wikipedia from IP addresses in the US Congress. Considering the US Congress is made up of brainy policy wonks who love editing details, it's no surprise it's full of people who also love editing Wikipedia. The Zelda edit also shows that even the people in charge of dictating national policy aren't immune from having a little fun on Wikipedia's edit pages.
Given the fact that the Twitter bot documents a lot of different joke edits made from Congress, it's pretty safe to say that this is a troll from the US Congress hoping to get picked up by this very Twitter bot. There are also legitimate edits made from Congress as well, so either someone on Capitol Hill doesn't know the difference between Zelda and Link, or it's just a vindictive jerk that wants to rile up a few gamers. Either way, that's a poor showing for the people who are supposed to be running our country.
Other edits made from Congress includes a change made to the Bandwidth Throttling article that dunks on Ajit Pai, a change to Supreme Leader Snoke's page that says he's secretly Jar Jar Binks (he's not), and an edit to the Mountain Dew page that asks, "do u dew the dew baby?"