Add CMake build

[synthfi]

Changes

• Adds a cmake build
• adds basic cpack integration

Notes

cmake -B build         # generate build directory
cmake --build build # build rolldice

packaging

cd build
cpack -G RPM # on fedora based distros
cpack -G DEB # on debian based distros

I don't know if I set up the deb package dependencies correctly

[synthfi]

rolldice isn't packaged in the dnf repos for aarch64, so I threw together something so that I could make a package and install it on my own system. Prefer this over a plain old install as files get tracked properly. Threw it your way just in case you find it useful at all~ I only know a bit of cmake, dunno how package maintainers like it to be

[synthfi]

pushed up some changes so that the it will default to installing rolldice in ${CMAKE_INSTALL_PREFIX}/games, but this can be overridden by modifying CMAKE_INSTALL_GAMEDIR in the cache.

example package contents when I build on asahi:

rpm -qlp build/rolldice-1.16-Linux.rpm

/usr/local
/usr/local/games
/usr/local/games/rolldice
/usr/share/man
/usr/share/man/man6
/usr/share/man/man6/rolldice.6.gz

in any case, I'm able to run rolldice on my laptop with a man page. happy now