Save canvas as excalidraw file and l10n support

[ralfi]

Hi,

if you use the libraries from excalidraw please add the option to export the canvas as excalidraw file and set the l10n to autodetect.

Thanks a lot for great work to add this in nextcloud.
Regards, ralfi

[juliusknorr]

Thanks for your feedback. Please check existing issues as there are already ones tracking those:

#50
#63