fix what a 1.0 would have welded into PyPI metadata

An adversarial review of the release, and four of its findings were things
PyPI never lets you replace once uploaded.

  - rust-version said 1.74. clap has needed 1.85 since 4.6, and cargo
    hard-errors rather than warning, so the sdist advertised a floor it could
    not build on. docs/releasing.md sends macOS and Windows users to that
    sdist.
  - The wheel was classified Development Status :: 4 - Beta on a release the
    changelog calls stable, with none of the Python version classifiers PyPI
    indexes on.
  - Six README links were relative. PyPI resolves them against the project
    page, so every one 404'd there, as they do on the live 0.2.0 page now.
  -  in that order packs the wheel into the
    sdist. The tarball on disk was 431KB with an x86-64 binary inside it.

Also: twine upload gains --skip-existing, so a retry after a partial upload
finishes rather than dying on a version that cannot be reused; twine check
gains the renderer that makes it parse the description at all, without which
it returns None and reports PASSED; and the README no longer claims a
twenty-year sweep the test did not run, because 366 * 21 / 4 is five years.
The test now runs the twenty-one it was named for.

The crates.io name belongs to an unrelated project, which the README now says
rather than leaving a reader to find out from cargo.

python/typikon/__init__.py

@@ -4,15 +4,17 @@ Everything derives from the paschalion and the fixed calendar, so this needs no
 network, cannot go stale, and answers for any year you ask about.
 
     >>> import typikon, datetime
-    >>> day = typikon.describe(datetime.date(2026, 4, 12))
+    >>> day = typikon.describe(datetime.date(2026, 4, 12), jurisdiction='new')
     >>> day.feast
     'The Radiant and Life-giving Resurrection of our Lord — Holy Pascha'
     >>> day.fast, day.days_to_pascha
     ('none', 0)
 
-Called without a jurisdiction, every function uses the one `typikon
---set-default` wrote, so the library and the command line agree about the same
-date. Pass ``jurisdiction=`` to override it; ``jurisdictions()`` lists the keys.
+The jurisdiction is given here because 12 April 2026 is Pascha on the Julian
+paschalion and an ordinary Sunday on the Gregorian one. Called without one,
+every function uses whatever `typikon --set-default` wrote, so the library and
+the command line agree about the same date. Pass ``jurisdiction=`` to override
+it; ``jurisdictions()`` lists the keys.
 """
 
 from ._typikon import (