Automatically create and upload release artifacts

Fixes #20

When a new tag is pushed, build updated artifacts and then create and upload them to a a new release using the same template text for the release description as in the link in the [release checklist for matHELICS](https://github.com/GMLC-TDC/HELICS/blob/main/.github/RELEASE_CHECKLIST_TEMPLATE.md).

.github/workflows/ci.yml

@@ -2,12 +2,13 @@ name: Test matHELICS
 
 on:
   push:
+    tags:
+      - 'v*.*.*'
+      - main
   pull_request:
     branches:
       - main
   workflow_dispatch:
-  #schedule:
-  #  - cron: "35 10 * * 1,3,5 # running early in the morning (UTC)
 
 jobs:
   ci-test:
@@ -39,11 +40,18 @@ jobs:
         uses: matlab-actions/run-command@v2
         with:
           command: buildHelicsInterface('helics',true)
+      - name: Rename artifact
+        run: |
+          if [[ ${{ runner.os }} == 'Windows' ]]; then
+            mv matHELICS.zip matHELICS-${{ matrix.os }}.zip
+          else
+            mv matHELICS.tar.gz matHELICS-${{ matrix.os }}.tar.gz
+          fi
       - name: store package
         uses: actions/upload-artifact@v4
         with:
           name: ${{ matrix.os }}-matHELICS
-          path: matHELICS.*
+          path: matHELICS-${{ matrix.os }}.*
       - name: run startup
         uses: matlab-actions/run-command@v2
         with:
@@ -53,3 +61,22 @@ jobs:
         with:
           command: addpath('tests'),addpath('helics'),runAllTests
 
+  release:
+    if: startsWith(github.ref, 'refs/tags/')
+    runs-on: ubuntu-latest
+    needs: ci-test
+    steps:
+      - name: Download artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: *-matHELICS
+          path: ./artifacts
+          merge-multiple: true
+      - name: Create Release
+        uses: softprops/action-gh-release@v2
+        with:
+          make_latest: true
+          tag_name: ${{ github.ref }}
+          name: ${{ github.ref }}
+          body: Release for [HELICS ${{ github.ref }}](https://github.com/GMLC-TDC/HELICS/releases/tag/${{ github.ref }})
+          files: ./artifacts/matHELICS-${{ matrix.os }}.*