Fix Create React App warnings when using Mapbox react wrapper

.env

# This causes the CRA builder to honor the local `eslintConfig` in the project's `package.json`
# https://create-react-app.dev/docs/setting-up-your-editor/#experimental-extending-the-eslint-config
EXTEND_ESLINT=true

package.json (excerpt)

{
  "eslintConfig": {
    "extends": "react-app",
    "rules": {
      "react/style-prop-object": ["warn", {
        "allow": ["Mapbox"]
      }]
    }
  }
}

SomeReactComponent.js

return <Mapbox
  style="mapbox://styles/mymaps/asdfsadfdsafsdfafe"
  //...etc.
/>

The Mapbox component accepts a style attribute that is a string. Ordinarily this triggers a warning in the default eslint config provided by CRA:

./src/SomeReactComponent.js
    Line 344:7:  Style prop value must be an object  react/style-prop-object