Add a link to release notes in NuGet package

Author: fredericDelaporte

build-common/NHibernate.props

@@ -19,6 +19,7 @@
     <PackageIconUrl>https://raw.githubusercontent.com/nhibernate/nhibernate-core/master/logo/NHibernate-NuGet.png</PackageIconUrl>
     <PackageRequireLicenseAcceptance>false</PackageRequireLicenseAcceptance>
     <PackageLicenseUrl>https://raw.githubusercontent.com/nhibernate/nhibernate-core/master/LICENSE.txt</PackageLicenseUrl>
+    <PackageReleaseNotes>https://github.com/nhibernate/nhibernate-core/blob/$(VersionPrefix)/releasenotes.txt</PackageReleaseNotes>
     <RepositoryUrl>https://github.com/nhibernate/nhibernate-core.git</RepositoryUrl>
     <RepositoryType>git</RepositoryType>