(GH-11) Basic nuspec file for DLL

- So that we can ship both a Chocolatey Package and Nuget package, let's
have a nuspec file for the DLL and a nuspec file for the exe.

Author: gep13

Packaging/nuget/GitHubReleaseManager.Cli.nuspec

@@ -6,11 +6,11 @@
     <version>$version$</version>
     <authors>gep13</authors>
     <owners>gep13</owners>
-    <projectUrl>https://github.com/Particular/GitHubReleaseNotes</projectUrl>
+    <projectUrl></projectUrl>
     <description>Create release notes in markdown given a GH milestone</description>
     <tags>github release notes</tags>
   </metadata>
   <files>
-    <file src="..\..\BuildArtifacts\*.exe" target="tools" />
+    <file src="..\..\BuildArtifacts\GitHubReleaseManager.exe" target="tools" />
   </files>
 </package>

Packaging/nuget/GitHubReleaseManager.nuspec

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<package xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.microsoft.com/packaging/2010/07/nuspec.xsd">
+  <metadata xmlns="http://schemas.microsoft.com/packaging/2010/07/nuspec.xsd">
+    <id>GitHubReleaseManager</id>
+    <title>Generates release notes</title>
+    <version>$version$</version>
+    <authors>gep13</authors>
+    <owners>gep13</owners>
+    <projectUrl></projectUrl>
+    <description>Create release notes in markdown given a GH milestone</description>
+    <tags>github release notes</tags>
+  </metadata>
+  <files>
+    <file src="..\..\BuildArtifacts\GitHubReleaseManager.dll" target="tools" />
+  </files>
+</package>