🖊️ Improve UX for small viewports

[agoose77]

Right now, our small-screen book-theme behaviour is:

1. 
2. 
3. 
4. 
5. 
6. 

With this PR, it is

1. 
2. 
3. 
4. 
5. 
6. 

At a high level, we disable flex-wrap in the navbar, change the navbar to sticky, and prevent the logo from shrinking. Crucially, you can scroll to the right to view the overflowing UX elements

This starts to address jupyter-book/mystmd#948

Next steps will be to move the vanishing navigation bar to the primary sidebar, and probably move the logo_text too.

[changeset-bot]

🦋 Changeset detected

Latest commit: 751e468

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 12 packages

Name	Type
@myst-theme/site	Patch
@myst-theme/providers	Patch
@myst-theme/frontmatter	Patch
@myst-theme/diagrams	Patch
@myst-theme/jupyter	Patch
@myst-theme/styles	Patch
@myst-theme/common	Patch
@myst-theme/icons	Patch
@myst-theme/book	Patch
@myst-theme/article	Patch
myst-to-react	Patch
myst-demo	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[rowanc1]

Nice - this looks like an improvement. Can you add a changeset?!

[rowanc1]

Thank you for the pictures!

[agoose77]

Yes, I'll do that!

A note -- the ugly looking primary navigation is probably a user-error (too many items in the navigation) or a UX quirk that we have to accept. The only way to improve this AFAICT would be e.g. to collapse some of the menu items at intermediate sizes into a dropdown icon.

[rowanc1]

Sorry - merge conflict - can you resolve and feel free to merge!