Align project structure with silverbullet-plug-template

- Rename deno.jsonc to deno.json and update build tasks
- Add PLUG.md for SB v2 installation
- Update .gitignore to include .plug.js files
- Update README.md with new installation instructions
- Simplify GitHub workflow

deno.json

@@ -0,0 +1,25 @@
+{
+  "tasks": {
+    "build": "deno run -A https://github.com/silverbulletmd/silverbullet/releases/download/edge/plug-compile.js -c deno.json icalendar.plug.yaml",
+    "watch": "deno run -A https://github.com/silverbulletmd/silverbullet/releases/download/edge/plug-compile.js -c deno.json icalendar.plug.yaml -w",
+    "debug": "deno run -A https://github.com/silverbulletmd/silverbullet/releases/download/edge/plug-compile.js -c deno.json icalendar.plug.yaml --debug"
+  },
+  "lint": {
+    "rules": {
+      "exclude": [
+        "no-explicit-any"
+      ]
+    }
+  },
+  "fmt": {
+    "exclude": [
+      "*.md",
+      "**/*.md",
+      "*.plug.js"
+    ]
+  },
+  "imports": {
+    "@silverbulletmd/silverbullet": "jsr:@silverbulletmd/silverbullet@^2.3.0",
+    "ts-ics": "npm:ts-ics@2.4.0"
+  }
+}