tweak installation instructions

4 jobs for misc_fixes in 4 minutes and 54 seconds (queued for 12 seconds)
Status Job ID Name Coverage
  Test
passed #166276
test_min

00:01:46

passed #166277
test_mpi

00:03:12

passed #166278
test_mpi_fftw

00:03:42

passed #166279
test_mpi_fftw_hdf5

00:04:43

57.0%