fix(lib): add Angular v9 to version range of v1

Author: gund

README.md

@@ -8,6 +8,7 @@
 | Angular | ngx-element-boundary | NPM package                   |
 | ------- | -------------------- | ----------------------------- |
 | 10.x.x  | 1.x.x                | `ngx-element-boundary@^1.0.0` |
+| 9.x.x   | 1.x.x                | `ngx-element-boundary@^1.0.0` |
 
 _NOTE:_ For Angular versions below v10 it may work but was not tested.
 

projects/ngx-element-boundary/package.json

@@ -2,11 +2,11 @@
   "name": "ngx-element-boundary",
   "version": "0.0.0-development",
   "peerDependencies": {
-    "@angular/common": "^10.0.0",
-    "@angular/core": "^10.0.0",
-    "@angular/elements": "^10.0.0"
+    "@angular/common": ">=9.0.0",
+    "@angular/core": ">=9.0.0",
+    "@angular/elements": ">=9.0.0"
   },
   "dependencies": {
-    "tslib": "^2.0.0"
+    "tslib": ">=1.0.0"
   }
 }