Bump @primer/gatsby-theme-doctocat from 3.1.1 to 4.0.0 in /docs

[josepmartins]

What are you trying to accomplish?

• Bump Doctocat for a consistent reader experience when navigating between different implementation doc sites.
• Move section titles as Introduction NavItems in the Sidebar

Reference

• https://github.com/github/primer/issues/1192

Can these changes ship as is?

• [x] Yes, this PR does not depend on additional changes. 🚢

[changeset-bot[bot]]

🦋 Changeset detected

Latest commit: d60a328a53affc133515f315ec3222c64cbf593f

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

This PR includes changesets to release 1 package

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@primer/css	Patch

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[josepmartins]

I moved the old titles to new NavItems and change its label to Introduction. WDYT @langermank @lesliecdubs? I even thought of changing the page title to use "{SectionName} introduction" to be aligned with the navigation label.

[jonrohan]

Sorry wrongfully closed 🙇🏻