fix indexing causing main thread freeze, various polish

package-lock.json

@@ -25,6 +25,7 @@
         "mdast-util-find-and-replace": "^2.2.2",
         "mdast-util-to-string": "^3.2.0",
         "micromorph": "^0.4.5",
+        "plausible-tracker": "^0.3.8",
         "preact": "^10.14.1",
         "preact-render-to-string": "^6.0.3",
         "pretty-time": "^1.1.0",
@@ -3619,6 +3620,14 @@
         "url": "https://github.com/sponsors/jonschlinkert"
       }
     },
+    "node_modules/plausible-tracker": {
+      "version": "0.3.8",
+      "resolved": "https://registry.npmjs.org/plausible-tracker/-/plausible-tracker-0.3.8.tgz",
+      "integrity": "sha512-lmOWYQ7s9KOUJ1R+YTOR3HrjdbxIS2Z4de0P/Jx2dQPteznJl2eX3tXxKClpvbfyGP59B5bbhW8ftN59HbbFSg==",
+      "engines": {
+        "node": ">=10"
+      }
+    },
     "node_modules/preact": {
       "version": "10.15.1",
       "resolved": "https://registry.npmjs.org/preact/-/preact-10.15.1.tgz",