[docs] Add Toolpad Core template link

[bharatkashyap]

• Closes https://github.com/mui/toolpad/issues/4409
• To merge only after https://github.com/mui/toolpad/pull/4415 and https://github.com/mui/toolpad/pull/4449 are merged

Preview: https://deploy-preview-44415--material-ui.netlify.app/material-ui/getting-started/templates/

[mui-bot]

Netlify deploy preview

• docs/data/material/getting-started/templates/templates.md

Bundle size report

No bundle size changes (Toolpad) No bundle size changes

Generated by :no_entry_sign: dangerJS against 56a0626d98285c9738f68862f04e74c94cc39092

[oliviertassinari]

This relates to the discussion in https://github.com/mui/mui-private/pull/13, https://github.com/mui/mui-private/issues/648, and https://github.com/mui/mui-private/issues/569.

[prakhargupta1]

The preview image currently shows the login screen. Is is possible to show the Dashboard screen instead?