Easiest solution and always latest version:
run this curl in your gitbash:
curl -L -o /usr/bin/jq.exe https://github.com/stedolan/jq/releases/latest/download/jq-win64.exe
or manually save the jq-win64.exe in link above as jq.exe to your /usr/bin (which is in your git bash installation folder)
(if you are behind a proxy add the -x proxyhost:port)
