Consider using [!NOTE] blockquote for browser/platform compatibility notes

[jonasfj]

In: https://pub.dev/documentation/webcrypto/latest/webcrypto/AesCtrSecretKey/encryptBytes.html

And a few other places we write: **Remark** ... to indicate that a particular browser or platform doesn't support a particular feature.

Instead of using this form, it'd be cool to use the [!NOTE] format.

Example

[!NOTE] Remark Firefox does not implement counter rollover for AES-CTR correctly. Picking a sufficiently large length and using a counter that isn't filled with 0xff will likely avoid counter rollovers. See bug 1803105 for details.

Markdown

> [!NOTE]
> Remark Firefox does not implement counter rollover for AES-CTR correctly. Picking a sufficiently large `length` and using a `counter` that isn't filled with 0xff will likely avoid counter rollovers. See [bug 1803105](https://bugzilla.mozilla.org/show_bug.cgi?id=1803105) for details.

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I think this should work with recent versions of dartdoc too! :rocket:

We should test it out locally first, and we should make sure to migrate all such remarks in one PR.