accelerate makefiles

[mcandre]

Divide steps into more independent tasks.

Skip unneeded tasks in CI/CD jobs.

Explore -j (4) parallelism, particularly POSIX support.

• [x] buttery
• [x] cicada
• [x] factorio
• [x] harmonica
• [x] mage-extras
• [x] octane
• [x] rouge
• [x] slick
• [x] stank
• [x] sunshine
• [x] tug
• [x] crit
• [x] tinyrick
• [x] tinyrick_extras
• [x] unmake
• [x] rez
• [x] shifty
• [x] snek
• [x] swiper

[mcandre]

POSIX has yet to support a -j flag for parallelism.

Let's declare a minimum of GNU / BSD make in projects that use makefiles.

And create an alias of make that supplies -j 4.

[mcandre]

-j 4 appears to work as expected for GNU make.

BSD make documentation indicates similar support for the same CLI syntax.