Meson

docs: add nixd worker model #1768

Job	Run time
nix-build-develop-clang (none, release, true)	2m 53s
nix-build-develop-gcc (none, release, true)	3m 14s
nix-build-develop-clang (none, release, false)	2m 49s
nix-build-develop-gcc (none, release, false)	3m 13s
nix-build-develop-clang (none, debug, true)	2m 32s
nix-build-develop-gcc (none, debug, true)	3m 4s
nix-build-develop-clang (none, debug, false)	2m 35s
nix-build-develop-gcc (none, debug, false)	2m 59s
nix-build-develop-gcc (undefined, release, true)	6m 38s
nix-build-develop-gcc (undefined, release, false)	6m 48s
nix-build-develop-gcc (undefined, debug, true)	3m 37s
nix-build-develop-gcc (undefined, debug, false)	3m 39s
	44m 1s

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