Work towards https://github.com/dart-lang/sdk/issues/61876
* Make a few notes about support beginning with Dart 3.10.
* Make a few notes indicating that plugins can only analyze Dart
sources.
* Use the handy `> [!NOTE]` and `> [!WARNING]` syntax.
* Add a note about how plugins are resolved, and the dependency on
analysis_server_plugin ^0.3.0.
Change-Id: I6ed5b3611a0ab4ff005917b0c5cff1b6fa9d5c95
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/459240
Commit-Queue: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>