UnitsNet.Uwp.nuspec: Add tags uwp, uap, winrt, win10

Author: angularsen

Build/UnitsNet.Uwp.nuspec

@@ -18,7 +18,7 @@
     </releaseNotes>
     <copyright>Copyright © 2015 Andreas Gullberg Larsen</copyright>
     <language>en-US</language>
-    <tags>unit units measurement si metric imperial abbreviation abbreviations convert conversion parse c# .net immutable</tags>
+    <tags>unit units measurement si metric imperial abbreviation abbreviations convert conversion parse c# .net immutable uwp uap winrt win10</tags>
   </metadata>
   <files>
     <file src="Artifacts\Bin\Src\AnyCPU_Release\uap10.0\UnitsNet.*" target="lib/uap10.0" />