Shrinker Pro 1.0.1

Publish 1.0.0: install links, stable download asset, update feed

Adds an Install section to the README and teaches release.sh to emit a
second, byte-identical copy of the DMG named ShrinkerPro.dmg.

The two names serve consumers with opposite requirements. GitHub's
permanent download URL is .../releases/latest/download/<exact asset name>,
so a download button that survives every release needs a filename with no
version in it. Sparkle needs the reverse: generate_appcast derives the
enclosure URL from the versioned filename, and each release's asset has to
stay distinct. Uploading both costs 2.5MB and lets each have what it needs.

The copy is made after stapling and its ticket re-validated, because a copy
taken beforehand would look identical while needing a network round trip on
first launch — and would fail to open offline.

appcast.xml carries the 1.0.0 entry, signed with the release EdDSA key.
Publishing it is still a manual push; release.sh prints the steps.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UViFBUxU17vNiGaZY7p2so