[NTG-context] Typearea module fails with “Missing number”

[Wolfgang Schuster]

Peter Münster via ntg-context schrieb am 31.08.2022 um 23:16:
> On Mon, Aug 29 2022, Wolfgang Schuster via ntg-context wrote:
>
>> remove one pair of curly braces
> Hi Wolfgang,
>
> Thanks. Here a new version: http://pmrb.free.fr/tmp/t-typearea.zip

Even though the module works now with LMTX it needs a proper update to 
ensure
it can be used in future documents.

Another suggestion from myself is to use the \averagecharwidth length 
for the calculation
of the text width because it takes the document language into account.

Wolfgang