**Problem:**
Currently, it appears as if editors can add `mul` descriptions in the termbox. But when they try, they receive an error message, that says `mul` is not allowed for descriptions. We need to make this more intuitive.
**Notes:**
* Another task does the same thing for desktop (the original task was split into viewing T329644 and editing T338302).
* The reason is that we only allow the language code `mul` for Labels and Aliases and not for descriptions (T313027).
* A WM message for "-" (disabled field) should already exists by now (see T329644).
**Solution:**
* Remove descriptions for `mul` language code from the users' termbox workflow
**Mockups:**
{F36912939}
{F36912941}
| [[ https://www.figma.com/file/UMHGYSxln03lGx2z7GxzP2/Multiple-languages?type=design&node-id=620-5012&t=KvqPaS6KVxnGWI5s-0 | Link to Figma specs ]] |
**Acceptance criteria:**
[] When viewing an Item on mobile, the termbox shows "-" as a description for `mul` (see mockup).
[] When editing an Item on mobile, the termbox shows a disabled edit field for descriptions for `mul` (see mockup).
[] Release to test.wikidata.org
**Open questions:**
* UX: The dash symbol ("-") should be localized for it to be understood in all cultures (maybe a WM message already exists). There might be a better placeholder (e.g., text) that we might want to consider.