Add a keyboard shortcut to toggle the sidebar

[hamirmahal]

Problem

I have to manually click the small clickbox for the sidebar to toggle its visibility, or tab-navigate to it using my keyboard.

Proposed Solution

We add a keyboard shortcut to toggle the sidebar to improve the user experience (UX).

Notes

No response

[hamirmahal]

The keyboard shortcut should be a sane default. https://chat.openai.com/, which people are likely familiar with, uses Ctrl + Shift + S as the default shortcut to toggle the sidebar.