docs: mention "next" tag in readme

Author: aleclarson

readme.md

@@ -16,7 +16,12 @@ This library represents a modern approach to animation. It is very much inspired
 
     npm install react-spring
 
+Try the beta for [v9.0.0](https://github.com/react-spring/react-spring/pull/632):
+
+    npm install react-spring@next
+
 ### Documentation and Examples
+
 More info about the project can be found [here](https://www.react-spring.io).
 
 Examples and tutorials can be found [here](https://www.react-spring.io/docs/hooks/basics).
@@ -25,15 +30,15 @@ Examples and tutorials can be found [here](https://www.react-spring.io/docs/hook
 
 ## Why springs and not durations
 
-The principle you will be working with is called a `spring`, it *does not have a defined curve or a set duration*. In that it differs greatly from the animation you are probably used to. We think of animation in terms of time and curves, but that in itself causes most of the struggle we face when trying to make elements on the screen move naturally, because nothing in the real world moves like that.
+The principle you will be working with is called a `spring`, it _does not have a defined curve or a set duration_. In that it differs greatly from the animation you are probably used to. We think of animation in terms of time and curves, but that in itself causes most of the struggle we face when trying to make elements on the screen move naturally, because nothing in the real world moves like that.
 
 <p align="middle">
   <img height="250" src="https://i.imgur.com/7CCH51r.gif" />
 </p>
 
-We are so used to time-based animation that we believe that struggle is normal, dealing with arbitrary curves, easings, time waterfalls, not to mention getting this all in sync. As Andy Matuschak (ex Apple UI-Kit developer) [expressed it once](https://twitter.com/andy_matuschak/status/566736015188963328): *Animation APIs parameterized by duration and curve are fundamentally opposed to continuous, fluid interactivity*.
+We are so used to time-based animation that we believe that struggle is normal, dealing with arbitrary curves, easings, time waterfalls, not to mention getting this all in sync. As Andy Matuschak (ex Apple UI-Kit developer) [expressed it once](https://twitter.com/andy_matuschak/status/566736015188963328): _Animation APIs parameterized by duration and curve are fundamentally opposed to continuous, fluid interactivity_.
 
-Springs change that, animation becomes easy and approachable, everything you do looks and feels natural by default. For a detailed explanation watch [this video](https://www.youtube.com/embed/1tavDv5hXpo?controls=1&amp;start=370).
+Springs change that, animation becomes easy and approachable, everything you do looks and feels natural by default. For a detailed explanation watch [this video](https://www.youtube.com/embed/1tavDv5hXpo?controls=1&start=370).
 
 ### What others say