Add 3.0.0 Release Notes (#337)

Author: kwart

distribution/doc/release-notes/3.0.0.md

@@ -0,0 +1,40 @@
+# Version 3.0.0
+
+Major release with a brand-new desktop UI and modernized Windows
+packaging.
+
+## Highlights
+
+- **New JavaFX GUI** — a document-centric desktop experience with PDF
+  preview, drag-to-place visible signatures, zoom/page navigation,
+  drag-and-drop PDF loading, progress indication, and a collapsible
+  side panel for signing options. The legacy Swing UI remains available
+  as a fallback via `-Djsignpdf.swing=true`. Encrypted PDFs are now
+  handled properly in the preview/signing flow.
+- **New Windows installers built with `jpackage`** — replacing the old
+  InnoSetup + Launch4j + Ant + Wine toolchain. Each release now ships
+  three Windows x64 artifacts: an EXE installer, an MSI installer, and
+  a portable ZIP with a bundled JRE. 32-bit Windows is no longer
+  supported (Temurin no longer ships 32-bit JDKs); 32-bit and
+  Linux/macOS users can still use the cross-arch `jsignpdf-<VERSION>.zip`
+  with their own JRE.
+- **Java 11 is now the minimum** runtime.
+
+## Other changes
+
+- "Reset Settings" action added to the JavaFX UI.
+- New and updated translations (Czech, German, French, Spanish, Slovak,
+  Portuguese, Croatian, Simplified Chinese, Traditional Chinese, and
+  more — thanks to all Weblate contributors).
+- Per-version release notes files are now attached as the GitHub
+  Release body.
+- User guide restructured around the new JavaFX UI, with a shared
+  UI-agnostic "Signing options" reference chapter and a small
+  Swing-for-backward-compatibility subsection.
+- Improved symlink handling, including macOS (#168).
+- Integration tests added for the PDF signing pipeline (#293).
+- Moved publishing from OSSRH to Maven Central.
+- Numerous dependency and GitHub Actions updates.
+
+Thanks to everyone who contributed code, translations, bug reports,
+and feedback!