add initial version of feature_member_reactives.adoc #338

Job	Run time
build (g++-10, Debug, 17)	2m 11s
build (g++-10, Release, 17)	2m 7s
build (clang++-10, Debug, 17)	1m 51s
build (clang++-10, Release, 17)	2m 27s
build (g++-7, Debug, 17, sudo apt-get install g++-7)	2m 12s
build (g++-11, Debug, 20, sudo apt-get install g++-11)	3m 31s
build (clang++-6.0, Debug, 17, sudo apt-get install clang-6.0)	2m 16s
build (clang++-7, Debug, 17, -stdlib=libc++, sudo apt-get install clang-7 libc++-7-dev libc++abi-...	2m 33s
build (clang++-7, Release, 17, sudo apt-get install clang-7)	2m 1s
build (clang++-11, Debug, 20, -stdlib=libc++, sudo apt-get install clang-11 libc++-11-dev libc++a...	2m 4s
build (clang++-11, Release, 20, sudo apt-get install clang-11)	3m 48s
build (sanitizers, clang++-12, Debug, 20, -O1 -g -fsanitize=address,undefined,leak,integer -fno-o...	4m 13s
build (valgrind-memcheck, g++-10, Debug, 17, -O1 -g -fno-omit-frame-pointer -fno-optimize-sibling...	2m 30s
build (coverage, g++-10, Debug, 17, -g -O0 --coverage -fno-inline, sudo apt-get install -y lcov, ...	2m 21s
	36m 5s

Provide feedback