Create platform for users to pair program

Add platform / section to DeepNote for people to organize and pair program. As DeepNote has this capabilities it would we shame not to encourage this.

Benefits of pair programming:
The idea is two developers work on the same machine. Both have keyboard and mouse. At any given time one is driver and the other navigator. The roles switch either every hour, or whenever really. The driver codes, the navigator is reading, checking, spell-checking and sanity testing the code, whilst thinking through problems and where to go next. If the driver hits a problem, there are two people to find a solution, and one of the two usually has a good idea.

Other advantages include the fact that where two people have differing specialities, these skills are transferred. Ad-hoc training occurs as one person shows the other some tricks, nice workarounds, etcetera.

The end result is that both developers are fully aware of the code, how it works, and why it was done that way. Chances are the code is better than one developer working alone, as there was somebody watching. It's less likely to contain bugs and hacks and things that cause maintenance problems later.

In a bigger team, the pairing can change each week so each team member is partnered with somebody different. This is a huge advantage, as it gets developers talking and communicating ideas in the common language of code.

We found this to be as fast as working separately. The code got written quicker and didn't require revisiting. And when it did need to change, more than one person was familiar with the code.

Add comments navigator for quick view and access to comments

When notebooks is long you have to scroll all they way down and look carefully for comments. Would be great if there was a navigator for comments, similar as for table of contents. So you can click on a comment and it will jump to that comment in notebook.

Open notebook from github with a link, without deepnote account - view only, to run need to login (similar as in Colab)

Would be great to be able to open a notebook from github via link like it's possible on coalb:
 this link would open notebook from github on colab. without login i can view only and with login i can run it.
Could this be implemented in DeepNote? Thanks!