**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
* The n-dash symbol "–" (disabled field) needs to be translateable to be understood in all cultures (e.g. in Japanese).
**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).
[] The n-dash symbol "–" (disabled field) is localized (a new translation string was created, see 329644)
[] When editing an Item on mobile, the termbox shows a disabled edit field for descriptions for `mul` (see mockup).
[] Users of screen reader technology receive the right prompt in read and edit mode (see specs)
[] Release to test.wikidata.org