Add package readme

Use `README.md` as nuget package readme.

README.md

@@ -1,11 +1,14 @@
-# Overview
+# icu.net
+
+## Overview
 
 icu-dotnet is the C# wrapper for a subset of [ICU](https://icu.unicode.org/).
 
 > ICU is a mature, widely used set of C/C++ and Java libraries providing Unicode and Globalization support
 > for software applications. ICU is widely portable and gives applications the same results on all platforms
 > and between C/C++ and Java software.
 
+[![NuGet version (icu.net)](https://img.shields.io/nuget/v/icu.net.svg?style=flat-square)](https://www.nuget.org/packages/icu.net/)
 [![Build, Test and Pack](https://github.com/sillsdev/icu-dotnet/actions/workflows/CI-CD.yml/badge.svg)](https://github.com/sillsdev/icu-dotnet/actions/workflows/CI-CD.yml)
 
 ## Usage
@@ -115,4 +118,5 @@ The package installer should have added an import to the `*.csproj` file similar
 We love contributions! The library mainly contains the functionality we need for our products. If you
 miss something that is part of ICU4C but not yet wrapped in icu.net, add it and create a pull request.
 
-If you find a bug - create an issue on GitHub, then preferably fix it and create a pull request!
+If you find a bug - create an [issue on GitHub](https://github.com/sillsdev/icu-dotnet/issues/new/choose),
+then preferably fix it and create a pull request!

source/icu.net/icu.net.csproj

@@ -2,11 +2,8 @@
   <PropertyGroup>
     <RootNamespace>Icu</RootNamespace>
     <AssemblyName>icu.net</AssemblyName>
-    <Description>icu.net is a C# Wrapper around ICU4C
-
-This version of icu.net works with (more or less) any version of ICU4C.
-
-NOTE: this package contains the managed wrapper part of icu.net. You'll also have to have the unmanaged binaries of ICU installed. On Linux it is recommended to install the official ICU package that comes with the system. On Windows you can install one of the binary nuget packages, e.g. Icu4c.Win.</Description>
+    <Description>icu.net is a C# Wrapper around ICU4C</Description>
+    <PackageReadmeFile>README.md</PackageReadmeFile>
   </PropertyGroup>
   <!-- Full .NET Framework properties -->
   <PropertyGroup Condition="'$(TargetFramework)' != 'netstandard1.6'">
@@ -15,6 +12,7 @@ NOTE: this package contains the managed wrapper part of icu.net. You'll also hav
   <ItemGroup>
     <PackageReference Include="GitVersion.MsBuild" Version="5.10.3" PrivateAssets="all" />
     <PackageReference Include="JetBrains.Annotations" Version="2022.1.0" PrivateAssets="all" />
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="all" />
     <PackageReference Include="SIL.ReleaseTasks" Version="2.5.0" PrivateAssets="all" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFramework)' == 'netstandard1.6'">
@@ -36,6 +34,9 @@ NOTE: this package contains the managed wrapper part of icu.net. You'll also hav
 
   <ItemGroup>
     <None Include="App.config" Pack="true" PackagePath="contentFiles\any\any\$(AssemblyTitle).dll.config" />
+    <None Include="../../README.md" Pack="true" PackagePath="/">
+      <Link>README.md</Link>
+    </None>
   </ItemGroup>
 
   <Target Name="CollectRuntimeOutputs" BeforeTargets="_GetPackageFiles">