Make Higurashi console arc install requirements more clear

As the console arcs install over higurashi ep4, if the user already has a modded ep4 the install will fail as the installer stops once it realizes where are already some mod files in the folder.

We should make it more clear what the requirements are to install the console arcs. Could someone fill me in on how this should work?

Look at the installer script that handles mod detection and failure, likely in the main patcher code. Understand the current error message and where it appears. Then update the README or installation instructions to specify that the console arcs require a clean, unmodded Episode 4 installation.

Written by the indexing model from the issue text.