[issue37826] Document PEP 3134 in tutorials/errors.rst

[Inada Naoki]

Change by Inada Naoki <songofacandy at gmail.com>:


----------
nosy: +methane
nosy_count: 4.0 -> 5.0
pull_requests: +22073
pull_request: https://github.com/python/cpython/pull/23162

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue37826>
_______________________________________