Feature request: loading files in SWISH

[friguzzi]

Loading files in swish could be useful: for .pl files, one can always copy and paste the code but for notebooks this is not possible and uploading them could be useful.
One could then write a notebook, download it, modify it locally and the upload it.

[JanWielemaker]

This is provided:

• Create a notebook
• Add a cell (+)
• Select more
• Use Insert notebook from local file

As it inserts a notebook, this also allows you combine multiple notebooks into a single one.