Update doc site for v7 migration guides

[brandongregoryscott]

Overview A deployed version of the changes in this branch can be viewed here: http://eg.brandonscott.me

The most notable change is from the /introduction/v6-migration-guide route to a tabbed page at /introduction/migrations. The tab doesn't seem to be working on my deployed site (nor do the the Details/Properties tabs on the component pages).

Primary changes: https://eg.brandonscott.me/introduction/migrations -> V7 Migration Guide https://eg.brandonscott.me/introduction/migrations/v6 -> Original V6 migration guide https://eg.brandonscott.me/introduction/theming - Removed references to classic theme https://eg.brandonscott.me/introduction/what-is-new - Added v7 change overview https://eg.brandonscott.me/components/pulsar - Removed Nudge references, cleaned up examples https://eg.brandonscott.me/components/group - Ported over SegmentedControl documentation, cleaned up examples https://eg.brandonscott.me/components/tabs - Removed SidebarTab references

Screenshots (if applicable)

Documentation

• [ ] Updated Typescript types and/or component PropTypes
• [ ] Added / modified component docs
• [ ] Added / modified Storybook stories