UnhandledPromiseRejectionWarning: Unhandled promise rejection

[ZouZou]

I am just starting with this repo, I did everything according to the docs however when I finish the last step and get the following:

Success! Created openapi folder.
You can run several commands:

npm start
Starts the development server.

npm run build
Bundles the definition.

npm test
Validates the definition.

We suggest that you begin by typing:

npm start

I try to use npm start and i get the below:

(node:29112) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): YAMLException: unknown escape sequence at line 3, column 18:
main: "openapi\openapi.yaml"
^
(node:29112) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

Can you help please?

[RomanHotsiy]

Dup of Redocly/redocly-cli#110