Expand the explanation of how to go and do useful work in non-blocking #870

Job	Run time
address_ub_sanitizer	15m 6s
basic_clang	7m 22s
basic_gcc	9m 3s
check_docs	1m 22s
check-ansi	4m 32s
check_update	1m 39s
enable_brotli_and_zstd_dynamic	7m 13s
enable_brotli_dynamic	7m 7s
enable_non-default_options	7m 23s
fips_and_ktls	7m 59s
enable_zstd_dynamic	8m 54s
memory_sanitizer	19m 16s
minimal	3m 39s
no-deprecated	7m 19s
non-caching	18m 12s
no-shared (ubuntu-latest)	5m 31s
no-shared (macos-latest)	9m 25s
threads_sanitizer	6m 36s
buildtest	11m 35s
enable_brotli_and_asan_ubsan	17m 37s
enable_zstd_and_asan_ubsan	13m 1s
enable-tfo (ubuntu-latest)	8m 31s
enable-tfo (macos-latest)	11m 45s
legacy	6m 48s
no-legacy	7m 51s
out-of-source-and-install (ubuntu-latest)	13m 33s
out-of-source-and-install (macos-latest)	17m 42s
external-test-cf-quiche	6m 20s
external-test-pyca (1.51.0, 3.9)	10m 24s
external-tests	16m 57s
	4h 49m 42s

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