Suggestion: Replace Download Icon in Notebook to match the actual one

[hsluytergaethje]

From internal review:
In the notebooks, the arrow depiction for "Local Mode" should match the download icon on the website.

[hsluytergaethje]

Since for this, we'd need to include an image, I'd suggest to leave the arrow icon as is. @DanilSko would do you think?

[DanilSko]

To me the arrow in the text seems understandable enough :) So I'd wait for at least one more person to complain before we change this