Module parse failed: Unexpected token

Hi @Grsmto – thanks for this plugin!

Unfortunately after following the install instructions I'm receiving the below error. I have added an access token to './config/mapbox-input.json', with no success.

Do you have any advice to get this up and running?

```
Error in ./node_modules/@math.gl/web-mercator/dist/esm/fly-to-viewport.js
Module parse failed: Unexpected token (50:17)
You may need an appropriate loader to handle this file type.
| }
| export function getFlyToDuration(startProps, endProps, options) {
| const opts = { ...DEFAULT_OPTS,
| ...options
| };
@ ./node_modules/@math.gl/web-mercator/dist/esm/index.js 6:0-79
@ ./node_modules/react-map-gl/node_modules/viewport-mercator-project/module.js
@ ./node_modules/react-map-gl/dist/esm/index.js
@ ./node_modules/sanity-plugin-mapbox-input/lib/GeopointInput.js (part:@sanity/form-builder/input/geopoint)
@ ./node_modules/@sanity/form-builder/lib/legacyParts.js
@ ./node_modules/@sanity/form-builder/lib/sanity/SanityFormBuilderContext.js
@ ./node_modules/@sanity/form-builder/lib/sanity/legacyPartImplementations/form-builder.js (part:@sanity/form-builder)
@ ./node_modules/@sanity/desk-tool/lib/panes/document/documentPanel/documentViews/FormView.js
@ ./node_modules/@sanity/desk-tool/lib/panes/document/documentPanel/documentViews/index.js
@ ./node_modules/@sanity/desk-tool/lib/panes/document/documentPanel/DocumentPanel.js
@ ./node_modules/@sanity/desk-tool/lib/panes/document/documentPanel/index.js
@ ./node_modules/@sanity/desk-tool/lib/panes/document/DocumentPane.js
@ ./node_modules/@sanity/desk-tool/lib/panes/document/index.js
@ ./node_modules/@sanity/desk-tool/lib/panes/DeskToolPane.js
@ ./node_modules/@sanity/desk-tool/lib/panes/index.js
@ ./node_modules/@sanity/desk-tool/lib/DeskTool.js
@ ./node_modules/@sanity/desk-tool/lib/_parts/base-tool.js
@ ./node_modules/@sanity/vision/lib/VisionTool.js (all:part:@sanity/base/tool)
@ ./node_modules/@sanity/default-layout/lib/util/getRegisteredTools.js
@ ./node_modules/@sanity/default-layout/lib/router.js
@ ./node_modules/@sanity/default-layout/lib/Root.js (part:@sanity/base/root)
@ ./node_modules/@sanity/base/lib/components/SanityRoot.js (part:@sanity/base/sanity-root)
@ ./node_modules/@sanity/server/lib/browser/entry-dev.js
@ multi ./node_modules/@sanity/server/lib/browser/entry-dev.js

Error in ./node_modules/mjolnir.js/dist/esm/event-manager.js
Module parse failed: Unexpected token (50:25)
You may need an appropriate loader to handle this file type.
| this.manager.emit(event.type, event);
| };
| this.options = { ...DEFAULT_OPTIONS, ...options };
| this.events = new Map();
| this.setElement(element);
@ ./node_modules/mjolnir.js/dist/esm/index.js 1:0-58
@ ./node_modules/react-map-gl/dist/esm/components/interactive-map.js
@ ./node_modules/react-map-gl/dist/esm/index.js
@ ./node_modules/sanity-plugin-mapbox-input/lib/GeopointInput.js (part:@sanity/form-builder/input/geopoint)
@ ./node_modules/@sanity/form-builder/lib/legacyParts.js
@ ./node_modules/@sanity/form-builder/lib/sanity/SanityFormBuilderContext.js
@ ./node_modules/@sanity/form-builder/lib/sanity/legacyPartImplementations/form-builder.js (part:@sanity/form-builder)
@ ./node_modules/@sanity/desk-tool/lib/panes/document/documentPanel/documentViews/FormView.js
@ ./node_modules/@sanity/desk-tool/lib/panes/document/documentPanel/documentViews/index.js
@ ./node_modules/@sanity/desk-tool/lib/panes/document/documentPanel/DocumentPanel.js
@ ./node_modules/@sanity/desk-tool/lib/panes/document/documentPanel/index.js
@ ./node_modules/@sanity/desk-tool/lib/panes/document/DocumentPane.js
@ ./node_modules/@sanity/desk-tool/lib/panes/document/index.js
@ ./node_modules/@sanity/desk-tool/lib/panes/DeskToolPane.js
@ ./node_modules/@sanity/desk-tool/lib/panes/index.js
@ ./node_modules/@sanity/desk-tool/lib/DeskTool.js
@ ./node_modules/@sanity/desk-tool/lib/_parts/base-tool.js
@ ./node_modules/@sanity/vision/lib/VisionTool.js (all:part:@sanity/base/tool)
@ ./node_modules/@sanity/default-layout/lib/util/getRegisteredTools.js
@ ./node_modules/@sanity/default-layout/lib/router.js
@ ./node_modules/@sanity/default-layout/lib/Root.js (part:@sanity/base/root)
@ ./node_modules/@sanity/base/lib/components/SanityRoot.js (part:@sanity/base/sanity-root)
@ ./node_modules/@sanity/server/lib/browser/entry-dev.js
@ multi ./node_modules/@sanity/server/lib/browser/entry-dev.js
```

Reproduce the Sanity development build after following the installation instructions and configuring config/mapbox-input.json. Start with the dependency paths in the error, especially @math.gl/web-mercator, mjolnir.js, react-map-gl, and sanity-plugin-mapbox-input/lib/GeopointInput.js. Done means the development build completes without the module parse errors.

Written by the indexing model from the issue text.