docs: improve README with clearer structure and examples

Reorganize installation and build instructions with separate sections for
web, desktop, and Docker. Add quick start commands and move detailed
packaging info to PACKAGING.md.

README.md

@@ -1,38 +1,35 @@
 # Motionity
 
-This is a fork of the original project aiming to fix issues and add features.
+Web-based motion graphics editor with keyframing, masking, filters and text animations.
 
-## Running it
+This is a fork of the original [Motionity](https://github.com/alyssaxuu/motionity) by [@alyssaxuu](https://github.com/alyssaxuu), with bug fixes and enhancements.
 
+## Quick Start
+
+**Web (localhost only):**
 ```bash
-npm install      # ffmpeg.wasm is vendored out of node_modules, so this is required
-npm run vendor   # downloads the third-party libraries into src/vendor/
+npm install
+npm run vendor
 npm start  # http://127.0.0.1:8080
 ```
 
-Three packaged distributions are available — desktop (Windows `.exe`, Linux
-AppImage and Flatpak), a Docker image, and a bare-metal install. Build
-instructions for all of them are in [PACKAGING.md](PACKAGING.md).
-
+**Desktop:**
 ```bash
-npm run dev            # desktop app from source
-npm run dist:win       # Windows installer + portable exe
-npm run dist:linux     # AppImage + Flatpak
-npm run docker:build   # container image
+npm install
+npm run vendor
+npm run dev  # Electron app
 ```
 
-## Releasing
-
-```powershell
-./scripts/build-release.ps1                 # installers + SHA256SUMS.txt in dist/
-./scripts/publish.ps1 -PublishRelease       # + image push and Gitea release upload
+**Docker:**
+```bash
+npm run docker:build
+npm run docker:run  # http://localhost:8080
 ```
 
-`build-release.ps1` needs no credentials. `publish.ps1` needs a Gitea token with
-package read/write (image push) and `write:repository` (release upload), read
-from `$env:GITEA_TOKEN` or prompted for. `-BinariesOnly -NoBinaryBuild` retries a
-failed upload without rebuilding.
+Full build instructions (Windows installers, Linux AppImage/Flatpak) in [PACKAGING.md](PACKAGING.md).
 
-One rule applies to every target: browsers expose WebCodecs (the fast exporter)
-and IndexedDB (project saving) only in a secure context. `http://localhost`
-qualifies; a plain-HTTP LAN address does not. Serve it over TLS anywhere else.
+## Notes
+
+- `ffmpeg.wasm` is vendored; `npm install` + `npm run vendor` are required
+- WebCodecs and IndexedDB only work in secure context (`http://localhost` OK, plain HTTP over LAN is not)
+- Serve over TLS for remote access