blog external link tracking

package.json

@@ -5,6 +5,7 @@
   "main": "index.js",
   "dependencies": {
     "@extractus/feed-extractor": "^7.1.3",
+    "@mozilla/readability": "^0.6.0",
     "@msgpack/msgpack": "^3.0.0-beta2",
     "@quri/squiggle-lang": "^0.10.0",
     "@vscode/markdown-it-katex": "^1.1.0",
@@ -25,6 +26,8 @@
     "html-to-text": "^9.0.5",
     "idb": "^7.1.1",
     "js-xxhash": "^4.0.0",
+    "jsdom": "^26.0.0",
+    "json5": "^2.2.3",
     "markdown-it": "^14.1.0",
     "markdown-it-anchor": "^8.6.7",
     "markdown-it-container": "^4.0.0",