Multiple issues with Aladin galaxy filtering section

There are multiple issues with the Aladin galaxy filtering section.

1. There are two confusing menu selection instruction.

   None of the items in this one are actually menus or menu items:

   :menuselection:`Aladin data collections tree --> Select --> click on the catalog item --> in the popup window check --> by region & MOC`

   Only the first two items ion this one are menus or menu items:

   :menuselection:`Catalog --> Create a filter--> Properties --> Advanced mode -→  Or enter your filter definition`

   Please use :menuselection: only for GUI actions that really are selecting menu items from the menu bar.

2. When I enter ${Dist} > DISTMEAN-DISTSTD && ${Dist} < DISTMEAN+DISTSTD {draw} into the filter properties dialog box and click Apply, I get this error message:

   

   I think that this is because DISTMEAN and DISTSTD are not understood by Aladin, and the user is meant to look up their values from the FITS headers and to substitute them into the the filter string. If this is the case, then there are several steps missing from the instructions.