Update README_pypi.md

Author: nimaid

README_pypi.md

@@ -1,5 +1,5 @@
 # pixelgreat
-## A highly realistic RGB pixel filter.
+### A highly realistic RGB pixel filter.
 
 <p align="center"><img src="https://github.com/nimaid/pixelgreat/blob/main/docs/example.png?raw=true" width="800px" alt="Example of the effect"/></p>