Solving definitions issues

[fredericbarthelet]

Solving issues listed in https://github.com/serverless/typescript/README.md with solution for discontinued maintenance of json-schema-to-typescript -> bcherny/json-schema-to-typescript#347

[fredericbarthelet]

Switching to quicktype ?
-> https://github.com/quicktype/quicktype
-> https://dev.to/okeeffed/generating-types-from-json-schema-with-quicktype-1fh2

[fredericbarthelet]

Issue on custom property not accepting additional properties : glideapps/quicktype#1615

[spawn-guy]

it seems that s3 event definition is not correctly converted

https://github.com/serverless/typescript/blob/master/index.d.ts#L164

should be

            s3:
              | string
              | {
                  bucket: string | AwsCfFunction;
                  event?: string;
                  existing?: boolean;
                  rules?: {
                    suffix?: string;
                  }[] | {
                      prefix?: string;
                  }[];
                };
          }

as AJV schema wants only 1 property
Configuration warning at 'functions.lambda_name.events[0].s3.rules[0]': should NOT have more than 1 properties