Updated CI for automated releases.

.github/workflows/dotnet.yml

@@ -4,11 +4,11 @@ on:
   push:
     branches:
       - '*'
+    tags:
+      - 'v*'
   pull_request:
     branches:
       - '*'
-  release:
-    types: [published]
 
 jobs:
   build:
@@ -46,6 +46,18 @@ jobs:
       with:
         path: artifacts/*
 
+    - name: Create changelog
+      if: startsWith(github.ref, 'refs/tags/') && matrix.configuration == 'Release'
+      run: git log --pretty=format:"- %h %B" "$(git describe --abbrev=0 --tags $(git rev-list --tags --max-count=2) | Select -Last 1)..$(git describe --abbrev=0 --tags $(git rev-list --tags --max-count=2) | Select -First 1)" >> ${{ github.workspace }}/CHANGELOG.TXT
+
+    - name: Create release
+      uses: softprops/action-gh-release@v1
+      if: startsWith(github.ref, 'refs/tags/')
+      with:
+        name: "PDFiumCore ${GITHUB_REF#refs/*/} Released"
+        files: artifacts/*.nupkg
+        body_path: ${{github.workspace}}/CHANGELOG.TXT
+
     - name: Push Nuget packages
-      if: github.event_name == 'release' && matrix.configuration == 'Release'
+      if: startsWith(github.ref, 'refs/tags/') && matrix.configuration == 'Release'
       run: dotnet nuget push artifacts/**/*.nupkg --api-key ${{ secrets.ORG_NUGET_AUTH_TOKEN }} --skip-duplicate