Various updates to the 13.0 release notes.

• Remove extraneous quotes from attributes.

• Prefer active voice to passive voice when describing changes.

• Correct a few entries that claimed functionality changed when the associated changes were changes to the documentation.

• Move the VirtIO V1 comment to the device drivers section and make it more generic as well as adding missing context for Q35 (it's specific to QEMU).

• Trim the bhyve entries to not include changes already present in 12.2. Also, don't list bugfixes to previous changes, e.g. a single entry for VM snapshots is sufficient from a user's perspective.

• Replace some bhyve entries with broader entries such as support for LA57 and Hygon Dhyana.

• In the note about the i386 CPUTYPE, shift to present tense instead of future tense.

Reviewed by: gjb (earlier version)
Discussed with: emaste
Differential Revision: https://reviews.freebsd.org/D29244