docs: update outdated info, reword, reformat

Author: Taylor Payne

README.md

@@ -26,23 +26,16 @@ In addition, frontend-platform provides an extensible application initialization
 ## Getting started
 
 ### One-time setup if you have not upgraded node/npm
-IMPORTANT: There is now a new node/npm version being used by frontend-platform as of
-https://github.com/openedx/frontend-platform/pull/259
 
 #### Install nvm
-This is highly recommended to be able to leverage different node/npm versions.
-For a some time, different repositories may be using different versions of node/npm.
-
-Alternatively, please install node16 and npm8 for use with this repository.
+This is highly recommended to be able to leverage different node/npm versions. For some time, different repositories may be using different versions of node/npm.
 
 #### Switch to node/npm version for this repo
-```nvm use```
-if you don't have the right node/npm versions, nvm will instruct you to install those
+In the project’s root directory, run `nvm use` to set your environment to the correct node version. If the required node or npm versions are not installed, nvm will prompt you to install them.
 
 #### Clean out old node modules and reinstall
 This step is needed because node now uses a different package lock format, and it's important to reinstall
-dependencies based on this new package file. Delete node_modules, and issue an `npm ci`
-
+dependencies based on this new package file. Delete `node_modules`, and run `npm ci`.
 
 ### Standard getting started steps
 
@@ -98,7 +91,7 @@ initialize({
 });
 ```
 
-When using runtime configuration via `mergeConfig` noted above, `getConfig` must be called within a component's render lifecycle for the added keys and values to be returned in the configuration object. If `getConfig` is called outside of a component's render lifecycle, the custom configuration key/value pairs will not initially be part of the object returned by `getConfig`. For example:
+When using runtime configuration via `mergeConfig` as noted above, `getConfig` must be called within a component's render lifecycle for the added keys and values to be returned in the configuration object. If `getConfig` is called outside of a component's render lifecycle, the custom configuration key/value pairs will not initially be part of the object returned by `getConfig`. For example:
 
 ```jsx
 import { getConfig } from '@edx/frontend-platform/config';

src/config.js

@@ -40,10 +40,10 @@
  *
  * ###### JavaScript File Configuration
  *
- * Configuration variables can be supplied in an optional file named env.config.js.  This file must
- * export either an Object containing configuration variables or a function.  The function must
- * return an Object containing configuration variables or, alternately, a promise which resolves to
- * an Object.
+ * Configuration variables can be supplied in an optional file named env.config.js (it can also be
+ * a `.jsx`, `.ts`, or `.tsx` file).  This file must export either an Object containing configuration
+ * variables or a function.  The function must return an Object containing configuration variables or,
+ * alternately, a promise which resolves to an Object.
  *
  * Using a function or async function allows the configuration to be resolved at runtime (because
  * the function will be executed at runtime).  This is not common, and the capability is included
@@ -89,11 +89,9 @@
  *
  * Configuration variables can also be supplied using the "runtime configuration" method, taking
  * advantage of the Micro-frontend Config API in edx-platform. More information on this API can be
- * found in the ADR which introduced it:
+ * found in [the ADR which introduced it](https://github.com/openedx/edx-platform/blob/master/lms/djangoapps/mfe_config_api/docs/decisions/0001-mfe-config-api.rst).
  *
- * https://github.com/openedx/edx-platform/blob/master/lms/djangoapps/mfe_config_api/docs/decisions/0001-mfe-config-api.rst
- *
- * The runtime configuration method can be enabled by supplying a MFE_CONFIG_API_URL via one of the other
+ * The runtime configuration method can be enabled by supplying a `MFE_CONFIG_API_URL` via one of the other
  * two configuration methods above.
  *
  * Runtime configuration is particularly useful if you need to supply different configurations to
@@ -103,9 +101,9 @@
  *
  * ##### Initialization Config Handler
  *
- * The configuration document can be extended by
- * applications at run-time using a `config` initialization handler.  Please see the Initialization
- * documentation for more information on handlers and initialization phases.
+ * The configuration document can be extended by applications at run-time using a `config`
+ * initialization handler.  Please see the Initialization documentation for more information on
+ * handlers and initialization phases.
  *
  * ```
  * initialize({
@@ -114,7 +112,7 @@
  *       mergeConfig({
  *         CUSTOM_VARIABLE: 'custom value',
  *         LMS_BASE_URL: 'http://localhost:18001' // You can override variables, but this is uncommon.
-  *       }, 'App config override handler');
+ *       }, 'App config override handler');
  *     },
  *   },
  * });
@@ -163,7 +161,9 @@ function parseParagonThemeUrls(paragonUrlsJson) {
   } catch (err) {
     if (err instanceof SyntaxError) {
       // eslint-disable-next-line no-console
-      console.error('Unable to parse PARAGON_THEME_URLS JSON.\nPlease check https://github.com/openedx/frontend-platform/tree/master/docs/how_tos/theming.md for the expected formatting.\nAn empty object ({}) will be returned, which will cause the theming configuration to fall back to the installed packages.');
+      console.error(
+        'Unable to parse PARAGON_THEME_URLS JSON.\nPlease check https://github.com/openedx/frontend-platform/tree/master/docs/how_tos/theming.md for the expected formatting.\nAn empty object ({}) will be returned, which will cause the theming configuration to fall back to the installed packages.',
+      );
       return {};
     }
     // In case of a different type of error, return the error object itself
@@ -223,7 +223,7 @@ let config = {
  * ```
  *
  * @returns {ConfigDocument}
-  */
+ */
 export function getConfig() {
   return config;
 }
@@ -301,7 +301,9 @@ export function ensureConfig(keys, requester = 'unspecified application code') {
     keys.forEach((key) => {
       if (config[key] === undefined) {
         // eslint-disable-next-line no-console
-        console.warn(`App configuration error: ${key} is required by ${requester}.`);
+        console.warn(
+          `App configuration error: ${key} is required by ${requester}.`,
+        );
       }
     });
   });
@@ -340,7 +342,7 @@ export function getExternalLinkUrl(url) {
  * In its most basic form, the initialization process loads this document via `process.env`
  * variables.  There are other ways to add configuration variables to the ConfigDocument as
  * documented above (JavaScript File Configuration, Runtime Configuration, and the Initialization
- * Config Handler)
+ * Config Handler).
  *
  * ```
  * {