"build": {
          "builder": "@angular-devkit/build-angular:browser",
          "options": {

            // これを
            "outputPath": "dist/my-app",
            // このように修正
            "outputPath": "../docs",
            "baseHref": ".",

            "index": "src/index.html",
            "main": "src/main.ts",
            "polyfills": "src/polyfills.ts",