✏ README, fix start-once bug and refactor

- Added some configuration and running to README
- Refactored some code
- Fixed exception when stopping a start-once script
- Only allow running with pnpm
- Moved transactions into sparebank1Api.ts
- Formatted

jest.config.ts

@@ -16,9 +16,7 @@ const config: JestConfigWithTsJest = {
     // Resolve @/ module paths
     "@/(.*)": "<rootDir>/src/$1",
   },
-  setupFiles: [
-    "<rootDir>/config.ts",
-  ]
+  setupFiles: ["<rootDir>/config.ts"],
 }
 
 export default config