Added notice of experimental module imports in README

Author: TheLonelyAdventurer

README.md

@@ -6,6 +6,8 @@ A sass module loader plugin for esbuild.
 This plugin allows .scss and .sass files to be imported as modules in javascript
 files.
 
+> Note: this package is a module.
+
 ## Basic usge:
 
 ```js
@@ -22,6 +24,30 @@ await esb.build(
 );
 ```
 
+> Note: if you see an error in console like this:
+> ```js
+> node:internal/process/esm_loader:94
+>     internalBinding('errors').triggerUncaughtException(
+>                               ^
+>
+> Error [ERR_UNSUPPORTED_DIR_IMPORT]: Directory import 'node_modules\lodash\fp' is not supported resolving ES modules imported from node_modules\@squirrelnetwork\esbuild-sass-modules-plugin\src\esbuild-sass-modules-plugin.class.js
+> Did you mean to import lodash/fp.js?
+>       at new NodeError (node:internal/errors:371:5)
+>       at finalizeResolution (node:internal/modules/esm/resolve:412:17)
+>       at moduleResolve (node:internal/modules/esm/resolve:932:10)
+>       at defaultResolve (node:internal/modules/esm/resolve:1044:11)
+>       at ESMLoader.resolve (node:internal/modules/esm/loader:422:30)
+>       at ESMLoader.getModuleJob (node:internal/modules/esm/loader:222:40)
+>       at ModuleWrap.<anonymous> (node:internal/modules/esm/module_job:76:40)
+>       at link (node:internal/modules/esm/module_job:75:36) {
+>   code: 'ERR_UNSUPPORTED_DIR_IMPORT',
+>   url: 'file:///.../node_modules/lodash/fp'
+> }
+> ```
+> Then you need to
+> [add the flag](https://nodejs.org/api/cli.html#cli_experimental_specifier_resolution_mode)
+> `--experimental-specifier-resolution=node` when running node.
+
 ## Documentation
 
 See the [wiki](https://github.com/Squirrel-Network/esbuild-sass-modules-plugin/wiki/)