Update README.md

Author: jesusbotella

README.md

@@ -2,12 +2,13 @@
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-ngx-lazy-load-images is a image lazy load library for Angular 2+.
+ngx-lazy-load-images is a image lazy load library for Angular 9+.
 
 The library allows to lazy load images from your web application using the [MutationObserver](https://developer.mozilla.org/en/docs/Web/API/MutationObserver) and the [IntersectionObserver](https://developer.mozilla.org/en/docs/Web/API/IntersectionObserver). Images will be loaded as soon as they enter the viewport in a non-blocking way.
 
 It supports `<img>` tags as well as background images.
 
+Please check v1.x.x releases for support to older versions of Angular. ngx-lazy-load-images v2+ just supports Angular 9+.
 
 ## Installation
 You can install the library via npm with this command: