Fix remarklint whining

Author: alerizzo

README.md

@@ -59,13 +59,13 @@ $ openapi --help
     $ openapi --input ./spec.json --output ./generated --client xhr
 ```
 
-Documentation
-===
+## Documentation
+
 
 The main documentation can be found in the [openapi-typescript-codegen/wiki](https://github.com/ferdikoomen/openapi-typescript-codegen/wiki)
 
-Sponsors
-===
+## Sponsors
+
 
 If you or your company use the OpenAPI Typescript Codegen, please consider supporting me. By sponsoring I can free up time to give this project some love! Details can be found here: https://github.com/sponsors/ferdikoomen