CI: Switch to action-gh-release@v2 (#5)

This commit switches from deprecated 'actions/create-release@v1' to                                                                                           
'softprops/action-gh-release@v2' for creating releases, combining the
 creation and upload steps into a single action to streamline the
workflow.

Close #3

Author: eleanorLYJ

.github/workflows/main.yml

@@ -19,24 +19,14 @@ jobs:
         pip install pygments
     - name: make
       run: make
-    - name: create Release
-      id: create_Release
-      uses: actions/create-release@v1
+    - name: Create and Upload Release
+      id: release
+      uses: softprops/action-gh-release@v2
       env:
-        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} 
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
       with:
+        files: |
+          ./concurrency-primer.pdf
         tag_name: ${{ github.ref_name }}
-        release_name: Release ${{ github.ref_name }}
         body: |
-          Changes in this Release
-    - name: Upload Release Asset
-      id: upload-release-asset 
-      uses: actions/upload-release-asset@v1
-      env:
-        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-      with:
-        upload_url: ${{ steps.create_release.outputs.upload_url }} 
-        asset_path: ./concurrency-primer.pdf
-        asset_name: concurrency-primer.pdf
-        asset_content_type:  application/pdf 
-    
+          Changes in this Release