fix: replace docker-compose by docker compose due to GitHub removing support

Author: JavierCane

README.md

@@ -4,7 +4,7 @@
 * Local using:
     * `dotnet run --project apps/Mooc/Backend/Backend.csproj`
 * Docker using:
-    * `docker-compose up`
+    * `docker compose up`
 
 And then going to http://localhost:8030/health-check to check all is ok.