Update readme and workflow

Author: deanagan

.github/workflows/dotnet.yml

@@ -26,5 +26,12 @@ jobs:
       run: dotnet build --no-restore
     - name: Test
       run: dotnet test --no-build --verbosity normal
-    - name: Coverage
-      run: dotnet test --collect:"Code Coverage"
+    - name: Generate coverage report
+      run: |
+        cd ./Tests
+        dotnet test /p:CollectCoverage=true /p:CoverletOutput=TestResults/ /p:CoverletOutputFormat=lcov
+    - name: Publish coverage report to coveralls.io
+      uses: coverallsapp/github-action@master
+      with:
+        github-token: ${{ secrets.GITHUB_TOKEN }}
+        path-to-lcov: ./Tests/TestResults/coverage.info

README.md

@@ -1,6 +1,7 @@
 # C# Design Patterns
 
 [![.NET](https://github.com/deanagan/csharp-design-patterns/actions/workflows/dotnet.yml/badge.svg)](https://github.com/deanagan/csharp-design-patterns/actions/workflows/dotnet.yml)
+[![Coverage Status](https://coveralls.io/repos/github/deanagan/csharp-design-patterns/badge.svg?branch=master)](https://coveralls.io/github/deanagan/csharp-design-patterns?branch=master)
 
 ## csharp-design-patterns