Rename build to box2d build

Author: codingben

.github/workflows/build.yml renamed to .github/workflows/box2d-build.yml

@@ -1,4 +1,4 @@
-name: Build
+name: Box2D Build
 
 on:
   push:
@@ -20,5 +20,5 @@ jobs:
         uses: actions/setup-dotnet@v1
         with:
           dotnet-version: "5.0.x"
-      - name: Box2D Build
+      - name: Build
         run: dotnet build src/ -c Release