Update README.md fo beta1 release

Author: Jolanrensen

README.md

@@ -1,6 +1,6 @@
 # Kotlin DataFrame: typesafe in-memory structured data processing for JVM
 [![JetBrains incubator project](https://jb.gg/badges/incubator.svg)](https://confluence.jetbrains.com/display/ALL/JetBrains+on+GitHub)
-[![Kotlin component alpha stability](https://img.shields.io/badge/project-alpha-kotlin.svg?colorA=555555&colorB=DB3683&label=&logo=kotlin&logoColor=ffffff&logoWidth=10)](https://kotlinlang.org/docs/components-stability.html)
+[![Kotlin component beta stability](https://img.shields.io/badge/project-beta-kotlin.svg?colorA=555555&colorB=DB3683&label=&logo=kotlin&logoColor=ffffff&logoWidth=10)](https://kotlinlang.org/docs/components-stability.html)
 [![Kotlin](https://img.shields.io/badge/kotlin-2.0.20-blue.svg?logo=kotlin)](http://kotlinlang.org)
 [![Dynamic XML Badge](https://img.shields.io/badge/dynamic/xml?url=https%3A%2F%2Frepo1.maven.org%2Fmaven2%2Forg%2Fjetbrains%2Fkotlinx%2Fdataframe%2Fmaven-metadata.xml&query=%2F%2Fversion%5Bnot%28contains%28text%28%29%2C%22dev%22%29%29%20and%20not%28text%28%29%3D%221727%22%29%20%5D%5Blast%28%29%5D&label=Release%20version)](https://search.maven.org/artifact/org.jetbrains.kotlinx/dataframe)
 [![Dynamic XML Badge](https://img.shields.io/badge/dynamic/xml?url=https%3A%2F%2Frepo1.maven.org%2Fmaven2%2Forg%2Fjetbrains%2Fkotlinx%2Fdataframe%2Fmaven-metadata.xml&query=%2F%2Fversion%5Bcontains%28text%28%29%2C%22dev%22%29%5D%5Blast%28%29%5D&label=Dev%20version&color=yellow
@@ -38,6 +38,9 @@ You could find the following articles there:
 * [Rendering to HTML](https://kotlin.github.io/dataframe/tohtml.html#jupyter-notebooks)
 
 ### What's new
+
+1.0.0-Beta1: [Release notes](https://github.com/Kotlin/dataframe/releases/tag/v1.0.0-Beta1)
+
 Check out this [notebook with new features](examples/notebooks/feature_overviews/0.15/new_features.ipynb) in v0.15.
 
 The DataFrame compiler plugin has reached public preview!