update release notes

Author: kMutagene

README.md

@@ -32,6 +32,13 @@ Plotly.NET provides functions for generating and rendering plotly.js charts in *
 
 The most recent Plotly.NET package is [![](https://img.shields.io/nuget/vpre/Plotly.NET)](https://www.nuget.org/packages/Plotly.NET/).
 
+Plotly.NET also provides several extension packages:
+
+| Package Name| Plotly.NET.Interactive | Plotly.NET.ImageExport | Plotly.NET.CSharp |
+|---|---|---|---|
+| Description | Interactive formatting extension for .NET interactive notebooks| programmatic static image export | idiomatic C# API. Note that you can use the core API in C#, this package just removes some friction at some places.|
+| Nuget | [![](https://img.shields.io/nuget/vpre/Plotly.NET.Interactive)](https://www.nuget.org/packages/Plotly.NET.Interactive/) | [![](https://img.shields.io/nuget/vpre/Plotly.NET.ImageExport)](https://www.nuget.org/packages/Plotly.NET.ImageExport/) | [![](https://img.shields.io/nuget/vpre/Plotly.NET.CSharp)](https://www.nuget.org/packages/Plotly.NET.CSharp/) |
+
 ### For applications and libraries
 
  - dotnet CLI
@@ -91,6 +98,7 @@ dotnet add package Plotly.NET --prerelease
 Interactively:
 ```
 #i "https://www.myget.org/F/plotly-net-nightly/api/v3/index.json"
+#r "nuget:Plotly.NET, *-*"
 #r "nuget:Plotly.NET.Interactive, *-*"
 ```