DEV-636: do not show Install extension if extension installed

Author: bdrtsky

src/injected.js

@@ -2,6 +2,8 @@
 
 const detectors = require('vue-telemetry-analyzer/src/detectors')
 
+window.$vueTelemetryExtension = true
+
 async function analyze () {
   if (isBlacklisted(document.location.href)) return
   const originalHtml = await fetch(document.location.href).then(res => res.text())

src/manifest.json

@@ -10,7 +10,7 @@
   },
   "content_scripts": [
     {
-      "run_at": "document_idle",
+      "run_at": "document_start",
       "matches": [
         "<all_urls>"
       ],