Navigation links, goto links, and detail links all are handled with
JavaScript, pushing and popping state.
* MigrationInfo moved to migration_info.dart
* All logic for rendering the code and regions of a unit moved to new
UnitRenderer class.
* Navigation links work.
* Goto links work.
* Fresh reload works.
* New scrolling behavior to leave scrolling alone if target is already
in view.
* Removed index page in favor of regular page with blank code.
* Back and forward buttons work.
Change-Id: If2296ee576c45374c18e5ba71426bcbdc894b71f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/128360
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Samuel Rawlins <srawlins@google.com>
Sam Rawlins
3ab95a114c