comment spam with no install.txt and install instruction on wpmudev is vague

Hello, after I download comment spam plugin, when unzipping the plugin, I couldn't find the install.txt, and the instruction at https://premium.wpmudev.org/project/comment-spam-pack/installation/ is really vague. Why? When unzipping the plugin, I saw a directory and extra files. Should the directory custom-anti-spam and the files on the same level with this directory, all should be in mu-plugins?