Use target_include_directories to publicly expose include dir

[scribam]

To use discord-rpc in a project before this change:

add_subdirectory(discord-rpc)
target_include_directories(${PROJECT_NAME} PRIVATE discord-rpc/include)
target_link_libraries(${PROJECT_NAME} PRIVATE discord-rpc)

To use discord-rpc in a project after this change:

add_subdirectory(discord-rpc)
target_link_libraries(${PROJECT_NAME} PRIVATE discord-rpc)

[scribam]

Hey @p0358 , could you take a look at this when you get a chance? Thanks!

[scribam]

@p0358 gentle ping

[p0358]

Aaa, sorry for the big delay. Yeah this seems to be fine.