Manual: add warnings regarding the use of auxiliary variables

9 jobs for doc_aux in 114 minutes (queued for 7 seconds)
Status Name Job ID Coverage
  Build
passed build_binaries #32224

00:12:31

passed build_doc #32225

00:01:51

 
  Test
passed test_dynare++ #32229

00:11:45

passed test_matlab #32226

01:41:25

manual test_octave #32228
allowed to fail manual
manual test_old_matlab #32227
allowed to fail manual
 
  Pkg
passed pkg_macOS #32232
macOS

00:23:23

passed pkg_source #32230

00:02:30

passed pkg_windows #32231

00:18:30