Create shade folders and files

Add a shaders folder in your project root folder.

Create colour.vert and colour.frag in the shaders folder.

modify CMakeLists.txt

to include shader.cpp as follows

# adding source files to our exectuable programs
add_executable(run01 src/main.cpp src/glad.c src/shader.cpp)

copy shader files to the build directory

# copy shaders
add_custom_target(CopyShaders ALL
	COMMAND ${CMAKE_COMMAND} -E copy_directory
	"${CMAKE_CURRENT_SOURCE_DIR}/shaders"
	"${CMAKE_CURRENT_BINARY_DIR}/shaders"
)

add_dependencies(run01 CopyShaders)