Add release notes link to Nuspec

Author: borrrden

packaging/nuget/couchbase-lite-support-android.nuspec

@@ -12,7 +12,7 @@
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>Xamarin Android native libraries and support classes for Couchbase Lite .NET</description>
     <releaseNotes>
-        Couchbase Lite .NET Developer Build
+        https://developer.couchbase.com/documentation/mobile/2.1/couchbase-lite/csharp.html#release-notes
     </releaseNotes>
     <copyright>Copyright 2018</copyright>
     <tags>couchbase couchbase-mobile couchbase-lite sync database mobile netcore xamarin ios android windows linux mac osx nosql</tags>

packaging/nuget/couchbase-lite-support-ios.nuspec

@@ -12,7 +12,7 @@
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>Xamarin iOS native libraries and support classes for Couchbase Lite .NET</description>
     <releaseNotes>
-        Couchbase Lite .NET Developer Build
+        https://developer.couchbase.com/documentation/mobile/2.1/couchbase-lite/csharp.html#release-notes
     </releaseNotes>
     <copyright>Copyright 2018</copyright>
     <tags>couchbase couchbase-mobile couchbase-lite sync database mobile netcore xamarin ios android windows linux mac osx nosql</tags>

packaging/nuget/couchbase-lite-support-netdesktop.nuspec

@@ -12,7 +12,7 @@
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>.NET Core / .NET Framework native libraries and support classes for Couchbase Lite</description>
     <releaseNotes>
-        Couchbase Lite .NET Developer Build
+        https://developer.couchbase.com/documentation/mobile/2.1/couchbase-lite/csharp.html#release-notes
     </releaseNotes>
     <copyright>Copyright 2018</copyright>
     <tags>couchbase couchbase-mobile couchbase-lite sync database mobile netcore xamarin ios android windows linux mac osx nosql</tags>

packaging/nuget/couchbase-lite-support-uwp.nuspec

@@ -12,7 +12,7 @@
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>UWP native libraries and support classes for Couchbase Lite .NET</description>
     <releaseNotes>
-        Couchbase Lite .NET Developer Build
+        https://developer.couchbase.com/documentation/mobile/2.1/couchbase-lite/csharp.html#release-notes
     </releaseNotes>
     <copyright>Copyright 2018</copyright>
     <tags>couchbase couchbase-mobile couchbase-lite sync database mobile netcore xamarin ios android windows linux mac osx nosql</tags>

packaging/nuget/couchbase-lite.nuspec

@@ -12,7 +12,7 @@
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>A lightweight, document-oriented (NoSQL), syncable database engine for .NET</description>
     <releaseNotes>
-        Couchbase Lite .NET Developer Build
+        https://developer.couchbase.com/documentation/mobile/2.1/couchbase-lite/csharp.html#release-notes
     </releaseNotes>
     <copyright>Copyright 2014-2018</copyright>
     <tags>couchbase couchbase-mobile couchbase-lite sync database mobile netcore xamarin ios android windows linux mac osx nosql</tags>