[Issue 12858] Document opEquals usage in AAs

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=12858

--- Comment #4 from github-bugzilla at puremagic.com ---
Commit pushed to master at https://github.com/D-Programming-Language/dlang.org

https://github.com/D-Programming-Language/dlang.org/commit/32ff94d74167616e84ea77619c8e8f69767153ce
Merge pull request #612 from schveiguy/fix12858

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