git: openjdk/amber-docs: Update reconstruction-records-and-classes.md

[duke]

Changeset: 02f4a3da
Author:    Brian Goetz <brian at briangoetz.com>
Committer: GitHub <noreply at github.com>
Date:      2020-08-13 13:28:29 +0000
URL:       https://git.openjdk.java.net/amber-docs/commit/02f4a3da

Update reconstruction-records-and-classes.md

Clarify documentation convention for __byname.

! eg-drafts/reconstruction-records-and-classes.md