Add instructions for file browser to README
Add instructions for file browser to README

fbaumgardt/arethusa,PonteIneptique/arethusa,latin-language-toolkit/arethusa,alpheios-project/arethusa,latin-language-toolkit/arethusa,fbaumgardt/arethusa,Masoumeh/arethusa,alpheios-project/arethusa,alpheios-project/arethusa,Masoumeh/arethusa,fbaumgardt/arethusa,PonteIneptique/arethusa