feat(v2): add ability to hide doc sidebar

[lex111]

Motivation

This PR allows you to hide the doc sidebar along with increasing content column width.
This is useful when there is a lot of long content on the page and you want to focus on it. This feature can also be actively used on medium screens (e.g. on tablets).

GitBook and GitLab docs have a similar feature in, but there the content column width does not increase, which loses the meaning of this feature, in my view.

As a result, the user has the opportunity to expand the content area width by 300px (this is sidebar width) if they hides the sidebar (see screenshots below).

I would even recommend turning it on by default, because in reality few docs generators have this functionality, this will be our just one more advantage.

Have you read the Contributing Guidelines on pull requests?

Yes

Test Plan

Preview.

Before	After

Related PRs

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[lex111]

@yangshun what do you think of this feature? Actually, it did not take a lot of code to implement it, but it seems to me that this will be a useful feature for our users. Moreover, that is good from the point of view of UX.

[slorber]

Hi,

The feature looks a good idea to me, but I'm not a fan of having the collapsed sidebar still being visible (a matter of taste, but I see some apps do that as well).

This feature is mostly useful on medium screens, what about making the sidebar totally disappear, with an ability to toggle/pin it?
I'm thinking about something like:
https://codepen.io/Kristuff/pen/apEEYM

If we keep current designs, some details:

• During transitions, the sidebar should keep a constant width, otherwise there's FOUC due to text wrapping
• Not a fan of having the expansion icon so much at the bottom, i'd rather add it to the center of the sidebar with more paddings

[yangshun]

what do you think of this feature?

I like it, thanks for adding it! It's a nice addition

Not a fan of having the expansion icon so much at the bottom, i'd rather add it to the center of the sidebar with more paddings

Agreed, the current design works but can be made more aesthetically pleasing.

Some ideas:

Visible

Hidden

[yangshun]

Let's revisit this in future if/when Alexey is back. This was never published and it has a ton of merge conflicts now.