Include Adaptive card json in build output (#28)

### Summary & Motivation

The Adaptive Card Json files were not included in the build output, and
therefor the application crashed while trying to show a card to the
user.

### Atomic Changes
- Include Adaptive card json in build output

### Checklist

- [x] I have added a Label to the pull-request
- [x] I have added tests, and done manual regression tests
- [x] I have updated the documentation, if necessary

application/calendar-assistant/MicrosoftTeams/CalendarAssistant.MicrosoftTeams.csproj

@@ -8,6 +8,12 @@
         <Nullable>enable</Nullable>
     </PropertyGroup>
 
+    <ItemGroup>
+      <Content Include="AdaptiveCards\Cards\*.json">
+        <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+      </Content>
+    </ItemGroup>
+
     <ItemGroup>
         <ProjectReference Include="..\Core\CalendarAssistant.csproj" />
     </ItemGroup>