chore: update README and CONTRIBUTING (#486)

* chore: update README and CONTRIBUTING docs

* Update CONTRIBUTING.md

Co-authored-by: Dasa Paddock <dpaddock@esri.com>

* Update README.md

Co-authored-by: Dasa Paddock <dpaddock@esri.com>

---------

Co-authored-by: Dasa Paddock <dpaddock@esri.com>

CONTRIBUTING.md

@@ -1,15 +1,12 @@
-Esri welcomes contributions from anyone and everyone. Please see our
-[guidelines for contributing](https://github.com/esri/contributing).
-
 # Contributing to [ArcGIS Maps SDK for Javascript](http://js.arcgis.com)
 
-There are several ways you can ask for assistance or provide feedback on the [ArcGIS Maps SDK for Javascript](http://js.arcgis.com) from [Esri](https://www.esri.com/).
+Esri welcomes contributions from anyone and everyone. There are several ways you can ask for assistance or provide feedback on the [ArcGIS Maps SDK for Javascript](http://js.arcgis.com) from [Esri](https://www.esri.com/).
 
-* Contact [Esri Tech Support](https://support.esri.com/contact-tech-support)
-* Ask the [Esri community](https://community.esri.com/t5/arcgis-api-for-javascript/ct-p/arcgis-api-for-javascript)
+* Contact [Esri Tech Support](https://support.esri.com/en-us/contact)
+* Ask the [Esri community](https://community.esri.com/t5/arcgis-javascript-maps-sdk-questions/bd-p/arcgis-api-for-javascript-questions)
 
 # Contributing to this repo
 
-__NOTE__: The two arcgis-js-api.d.ts files are automatically created from source code, so no need to create pull requests for these generated files. However, feel free to report issues related to these files and we'll see if changes can be incorporated into our source code, and the next update of these generated files.
+__NOTE__: The [arcgis-js-api.d.ts](./typescript/archive) files are automatically created from source code for each release, so there is no need to create a pull requests to update them. However, feel free to report issues related to these files and we'll see if changes can be incorporated into our source code, and the next update of these generated files.
 
-For anything else in this repo, feel free to report issues and pull requests.
+For anything else in this repo, feel free to report issues before submitting a pull request.

README.md

@@ -1,30 +1,39 @@
 jsapi-resources
 ===============
-A collection of resources for developers using the [ArcGIS Maps SDK for JavaScript](https://js.arcgis.com).
+A collection of resources for developers using the [ArcGIS Maps SDK for JavaScript](https://js.arcgis.com). Refer to the README files in each subdirectory for specific instructions on how to use a particular resource. 
 
-## ArcGIS Maps SDK for JavaScript
+## ES modules (ESM) samples
 
-### 4.x
+The Maps SDK's ES modules are available through the [`@arcgis/core`](https://www.npmjs.com/package/@arcgis/core) package on NPM. TypeScript definitions are included in the install.
 
-#### ES modules (ESM)
-* [ESM samples - Create local builds with frameworks and module bundlers](./esm-samples/)
+Below are a collection of samples that provide _proof-of-concept_ for using `@arcgis/core` with a variety of popular JavaScript build tools, frameworks and module bundlers.  
 
-#### AMD modules
-* [TypeScript - Class and interface definitions](./4.x/typescript/README.md)
+* [Angular CLI](./esm-samples/jsapi-angular-cli/)
+* [ArcGIS ESM CDN](./esm-samples/jsapi-esm-cdn/)
+* [Custom workers](./esm-samples/jsapi-custom-workers/)
+* [Custom UI](./esm-samples/jsapi-custom-ui/)
+* [Deno](./esm-samples/jsapi-deno/)
+* [Node.js](./esm-samples/jsapi-node/)
+* [React/Vite](./esm-samples/jsapi-react/)
+* [Rollup.js (no framework)](./esm-samples/rollup/)
+* [Vue.js/Vite](./esm-samples/jsapi-vue/)
+* [Vite/TypeScript](./esm-samples/jsapi-vite-ts/)
+* [Webpack (no framework)](./esm-samples/webpack/)
 
-### OAuth
-* [HTML for handling callbacks](./oauth/README.md)
+## AMD TypeScript declaration files
 
-### 3.x (Legacy)
-* 3.x samples can be downloaded or [checked out](https://git-scm.com/book/en/v2/Git-Basics-Tagging) via the [`legacy` releases tag](https://github.com/Esri/jsapi-resources/releases/tag/legacy). 
+The TypeScript `.d.ts` files for the last several releases of the Maps SDK's AMD modules can be downloaded from this [repo](./4.x/typescript/README.md). Or, you can NPM install the [`arcgis-js-api`](https://www.npmjs.com/package/arcgis-js-api) package and the TypeScript definitions are included.
 
-## Instructions
-Refer to the README files in each subdirectory of this repo for specific instructions on how to use a particular resource.
+## HTML OAuth callback example
 
-## Troubleshooting
-For recommendations on identifying and solving issues in the ES module samples, see the [troubleshooting guide](./TROUBLESHOOTING.md).
+If you have set OAuthInfo's `popup` property to `true`, you'll need to host a callback page on your server. This repo contains an [example callback page](./oauth/). For more information, visit the Maps SDK's [Access secure resources(https://developers.arcgis.com/javascript/latest/secure-resources/)] guide topic.
+
+## 3.x (Legacy) samples
+
+Legacy 3.x Bower and TypeScript samples can be downloaded or [checked out](https://git-scm.com/book/en/v2/Git-Basics-Tagging) via the [`legacy` releases tag](https://github.com/Esri/jsapi-resources/releases/tag/legacy). 
+
+## Additional resources
 
-## Resources
 * [ArcGIS Maps SDK for JavaScript](https://js.arcgis.com)
 * [TypeScript](http://www.typescriptlang.org/)