docs: describe new props

README.md

@@ -36,7 +36,7 @@
 ```
 ### 2b: Install as a plugin 
 ```javascript
- import { Plugin } from 'vue-responsive-video-background-player'
+ import { Plugin } from 'vue-responsive-video-background-player'
 
  Vue.use(Plugin);
 ```
@@ -166,6 +166,18 @@ https://www.w3schools.com/tags/att_video_preload.asp
 
 So the video fits perfectly in the container
 
+- `objectPosition` (default: `center`)
+
+So the video fits exact position in the container
+
+> the value is also used as a poster background-position 
+
+- `posterBgSize` (default: `cover`)
+
+So the poster fits perfectly in the container
+
+> Using the same values for `objectFit` and `posterBgSize` is recommended
+
 - `playsWhen` (default: `canplay`)
 
 This is important, if you know that you might have users with bad internet speed, you should definetly use `canplaythrough`. Learn more in [video events](https://www.w3schools.com/tags/ref_av_dom.asp).