Remove npm run start script

It is superseded by the runtime flag `--custom-devtools-frontend`,
as documented in our README.

We can no longer keep this script around, as it blocks the inclusion
of TypeScript-authored files in the source tree.

[email protected],[email protected]

Design-Doc: https://docs.google.com/document/d/1COgCBWWuTh2o-Zbp6h_z0h0LtlJaimaEDsION4RZPxc/edit
Bug: 1061037, 1011811
Change-Id: Id7a347f28acf7a3a065c5c3dea4e74443d4ac7ed
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2247653
Commit-Queue: Tim van der Lippe <[email protected]>
Reviewed-by: Yang Guo <[email protected]>

Author: TimvdLippe

package.json

@@ -28,7 +28,6 @@
     "check-loc": "python scripts/test/run_localization_check.py",
     "check-type": "echo \"If you want to typecheck with TypeScript, run \\\"autoninja -C out/X\\\". If you want to typecheck with Closure, run \\\"npm run check-type-closure\\\"\"",
     "check-type-closure": "python scripts/test/run_type_check.py",
-    "chrome": "third_party/node/node.py scripts/hosted_mode/launch_chrome.js",
     "components-server": "third_party/node/node.py scripts/component_server/server.js",
     "debug-e2etest": "DEBUG=1 python scripts/test/run_test_suite.py --test-suite=e2e",
     "debug-test": "third_party/node/node.py scripts/npm_test.js --debug-devtools",
@@ -46,7 +45,7 @@
     "screenshottest": "python scripts/test/run_test_suite.py --test-suite=screenshots",
     "server": "third_party/node/node.py scripts/hosted_mode/server.js",
     "setup-dtrun": "cd scripts/devtools_run && npm link",
-    "start": "third_party/node/node.py scripts/hosted_mode/start_chrome_and_server.js",
+    "start": "node -e 'console.log(`This script has been removed in favor of --custom-devtools-frontend. For more information, see https://docs.google.com/document/d/1COgCBWWuTh2o-Zbp6h_z0h0LtlJaimaEDsION4RZPxc/edit?usp=sharing`);'",
     "test": "third_party/node/node.py scripts/npm_test.js",
     "test-local": "third_party/node/node.py scripts/npm_test.js --layout-tests-directory=test/webtests/",
     "ts_library-test": "./third_party/typescript/tests/verify_ts_libary.sh",