Beta releases (#363)

* Add pre-release support with "...-beta" tags

* Add "pre" as keyword for prereleases

* Use ref_name instead of ref

ref: The branch or tag ref that triggered the workflow run. For branches this is the format refs/heads/<branch_name>, and for tags it is refs/tags/<tag_name>.

ref_name: The branch or tag name that triggered the workflow run.

.github/workflows/release.yml

@@ -37,7 +37,7 @@ jobs:
 
       - name: Replace version with tag name
         run: |
-          sed -i "s/1.0.dev/${{ github.ref }}/g" $SCRIPTING_PATH/SurfTimer.sp
+          sed -i "s/1.0.dev/${{ github.ref_name }}/g" $SCRIPTING_PATH/SurfTimer.sp
 
       - name: Compile surftimer.sp
         run: |