I am trying to configure the repository languages bar in my repository. I found on the documentation that I needed to add *. linguist-detectable=true to the .gitattributes file. I tried to add .md, .png, .rst, and .txt to the bar. It has been two weeks and there is nothing new on the bar. Would someone be able to give me some help with this? Is there a list of languages that the bar can be configured to show?