docs: fix version finding

Author: hynek

.github/PULL_REQUEST_TEMPLATE.md

@@ -19,7 +19,8 @@ If an item doesn't apply to your pull request, **check it anyway** to make it ap
 - [ ] Updated **documentation** for changed code.
     - [ ] New functions/classes have to be added to `docs/api.rst` by hand.
     - [ ] Changed/added classes/methods/functions have appropriate `versionadded`, `versionchanged`, or `deprecated` [directives](http://www.sphinx-doc.org/en/stable/markup/para.html#directive-versionadded).
-      Find the appropriate next version in our [`__init__.py`](https://github.com/hynek/structlog/blob/main/src/structlog/__init__.py) file.
+
+      The next version is the second number in the current release + 1. The first number represents the current year. So if the current version on PyPI is 23.1.0, the next version is gonna be 23.2.0. If the next version is the first in the new year, it'll be 24.1.0.
 - [ ] Documentation in `.rst` and `.md` files is written using [**semantic newlines**](https://rhodesmill.org/brandon/2012/one-sentence-per-line/).
 - [ ] Changes (and possible deprecations) are documented in the [**changelog**](https://github.com/hynek/structlog/blob/main/CHANGELOG.md).
 - [ ] Consider granting [push permissions to the PR branch](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/allowing-changes-to-a-pull-request-branch-created-from-a-fork), so maintainers can fix minor issues themselves without pestering you.