Release v2.9.0

New Changes:

• Added colourless icon set (#4)
• Fixed updateGrub missing during uninstall (#5, #6)
• Build system fixes and improvements
• Updated README
• Updated icons: Android, Arch, Arco, Artix, Debian, Deepin, Elementary OS, find.efi, Gentoo, Generic Linux, Korora, KUbuntu, LUbuntu, Mac OSX, MX Linux, KDE Neon, OpenSUSE, Parrot, Peppermint OS, Pop! OS, Puppy Linux, Q4OS, SystemRescueCD, Ubuntu, Ubuntu Budgie, Ubuntu MATE and Ubuntu Studio