Fixed description and preview image in manifest (#22)

src/Testura.Mutation.VsExtension/source.extension.vsixmanifest

@@ -3,16 +3,11 @@
     <Metadata>
         <Identity Id="Testura.MutationVsExtension.71e8249a-b76c-4035-af2b-0304cbf33623" Version="1.1.0" Language="en-US" Publisher="Mille Boström" />
         <DisplayName>Testura.Mutation</DisplayName>
-        <Description xml:space="preserve">Are you looking for ways to improve the quality and test coverage of your unit tests? Then Testura and mutation testing may be something for you.
-
-Testura is a mutation testing extension for visual studio that verifies the quality of your unit tests by injecting different mutations in your production code and then checks whether your unit tests catch them. If your unit tests:
-
-- Fail it means that your tests found the mutation and you have good coverage.
-- Pass it means that the mutant survived and you do not have sufficient coverage of the specific functionality.</Description>
+        <Description xml:space="preserve">Testura is a mutation testing extension for visual studio that verifies the quality of your unit tests by injecting different mutations in your production code and then checks whether your unit tests catch them.</Description>
         <MoreInfo>https://github.com/Testura/Testura.Mutation</MoreInfo>
         <ReleaseNotes>https://github.com/Testura/Testura.Mutation/releases</ReleaseNotes>
         <Icon>Resources\bigIcon.png</Icon>
-        <PreviewImage>MutationWindow.PNG</PreviewImage>
+        <PreviewImage>Resources\bigIcon.png</PreviewImage>
         <Tags>Mutation tesing unit tests</Tags>
     </Metadata>
     <Installation>