This library isn't working.

まず、ダウンロードした zip から Processing 3.5.4 にインストールし、アーカイブ内のライブラリと JAR の命名を確認します。package の import と依存関係の構成を確認したうえで、競合するライブラリのエラーが発生せず、クリーンなインストールが Import Library に表示されることを検証します。

I downloaded the zip file and extracted it all into a new folder in "libraries" in my Processing folder, but when I would type "import processing.OpenSimplexNoise.*;" I got the message "The import processing.OpenSimplexNoise cannot be resolved." I discovered that this was because the library and JAR file didn't have the same name, and the "lib" folder should be "library."
I fixed these two issues, and then OpenSimplexNoise appeared in the Import Library menu, but when I did, a bunch of code appeared:

import japplemenubar.*;
import processing.awt.*;
import processing.core.*;
import processing.data.*;
import processing.event.*;
import processing.javafx.*;
import processing.opengl.*;

and the error message:

More than one library is competing for this sketch
The import japplemenubar points to multiple libraries:
core (C:\Program Files\Processing\processing-3.5.4\core)
OpenSimplexNoise (C:\Users**\Documents\Processing\libraries\OpenSimplexNoise)
Extra libraries need to be removed before this sketch can be used.

As far as I can tell, I haven't done anything incorrectly, and whatever's happening here is probably far beyond my understanding.