build: change peer dependency to range

Author: flaviorocks

src/package.json

@@ -25,6 +25,6 @@
   "module": "index.js",
   "typings": "ng2-pdfjs-viewer.d.ts",
   "peerDependencies": {
-    "@angular/core": "^11.2.3"
+    "@angular/core": "<=11"
   }
 }