Working with my own project lib instead of Arduino lib

I need some clarification when I wanna create a cpp Arduino code lets say for a oled and need the u8glib.h.
Well I can find the lib @ GitHub - olikraus/u8glib: Arduino Monochrom Graphics Library for LCDs and OLEDs. The question which rised when I download the zip. what Files do I need to copy into the lib directory of my project. Only the u8glib.h or extract and reanme the whole zip?

Any advice would be helpfull

Read the readme.txt in the lib folder of your project. For this project it seems that you should download the Arduino release version (Release 1.19.1 · olikraus/U8glib_Arduino · GitHub) and extract the folder in the lib folder of your project. The same source code can also be downloaded as a tar from the platformio page. So the project structure should become

- U8glib_Arduino-1.19.1/
---- examples/
---- extras/
---- src/
---- license.txt
- main.cpp

When you #include "U8glib.h" in your code file, platformio should choose the locally installed version in lib/. If not you use the exclusion options (lib_ignore) and more options described here.