[connect] Create one docs page to explain how to use MUI Connect

[oliviertassinari]

Summary 💡

Seed the first page of docs. The objective is to have a page developers can follow, ideally with a video demo

Examples 🌈

• https://docs.tokens.studio/sync/jsonbin
• https://www.antforfigma.com/docs/theme-buddy-figma-plugin
• https://www.ag-grid.com/javascript-data-grid/ag-grid-design-system/

Motivation 🔦

No response

How to distribute that docs

• Create the content at https://mui.com/figma/getting-started (Notion page)
• Add links to it from the Figma plugin community page (depending on [connect] Publish a Figma plugin #277)
• We move the docs from Notion to our docs-infra. We start with new pages in https://mui.com/material-ui/.
• Once the content becomes too large, move to https://github.com/mui/mui-design-kits/ to get isolation of focus

[dusskapark]

Looking forward to it!