Add description of JSON output folder

9 jobs for JSON_manual in 1 minute and 45 seconds (queued for 47 seconds)
Status Job ID Name Coverage
  Build
canceled #20198
build_binaries

passed #20199
build_doc

00:01:45

 
  Test And Pkg
skipped #20202
macOS
pkg_macOS
skipped #20200
pkg_source
skipped #20201
pkg_windows
skipped #20206
test_dynare++
skipped #20203
test_matlab
skipped #20205
allowed to fail manual
test_octave
skipped #20204
allowed to fail manual
test_old_matlab