Document Weeder usage #84

Job	Run time
build ucm (ubuntu-20.04)	27m 2s
ormolu	8s
build ucm (macOS-12)	45m 53s
build ucm (windows-2019)	31m 32s
generate jit source	12m 53s
run interpreter tests (ubuntu-20.04)	1m 9s
run transcripts (ubuntu-20.04)	4m 0s
run interpreter tests (macOS-12)	1m 51s
run transcripts (macOS-12)	6m 1s
run transcripts (windows-2019)	8m 6s
build jit binary / build jit binary (ubuntu-20.04)	1m 30s
build jit binary / build jit binary (macOS-12)	7m 58s
build jit binary / build jit binary (windows-2019)	6m 5s
test jit / test jit (ubuntu-20.04)	1m 34s
test jit / test jit (macOS-12)	2m 12s
	2h 37m 54s

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