Add installation link to readme. #917

Job	Run time
ubu-24 \| clang++-19 \| c++20 \| libstdc++ \| ubuntu-24.04	9m 39s
mac-14 \| clang++ \| c++2b \| default \| macos-14	3m 45s
ubu-22 \| clang++-15 \| c++20 \| libstdc++ \| ubuntu-22.04	6m 5s
ubu-22 \| clang++-15 \| c++20 \| libc++-15-dev \| ubuntu-22.04	6m 22s
win-22 \| cl.exe \| c++latest \| default \| windows-2022	36s
ubu-24 \| g++-13 \| c++2b \| libstdc++ \| ubuntu-24.04	7m 31s
win-22 \| cl.exe \| c++20 \| default \| windows-2022	54s
mac-13 \| clang++ \| c++2b \| default \| macos-13	8m 11s
ubu-24 \| clang++-19 \| c++23 \| libc++-18-dev \| ubuntu-24.04	9m 41s
mac-13 \| clang++-15 \| c++2b \| default \| macos-13	10m 12s
ubu-24 \| g++-14 \| c++2b \| libstdc++ \| ubuntu-24.04	9m 15s
aggregate-results	6s
	1h 12m 17s

Provide feedback