migrate kernel from C to C++
# Please enter the commit message for your changes. Lines starting
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# On branch main
# Your branch is up to date with 'origin/main'.
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# Changes to be committed:
#	modified:   Makefile
#	modified:   bin/CustomOS.img
#	modified:   bin/kernel.elf
#	new file:   lib/BasicRenderer.o
#	modified:   lib/kernel.o
#	new file:   src/BasicRenderer.cpp
#	new file:   src/BasicRenderer.h
#	new file:   src/Framebuffer.h
#	new file:   src/PSF1Font.h
#	deleted:    src/kernel.c
#	new file:   src/kernel.cpp
#	new file:   src/math.h
#