Update README to show more options for disabling and overrides (#165)

The new feature of disabling with empty array can do more than just
disabling globally and enabling for certain folders or files. It can do
the opposite: enabling globally and disabling for certain folders or
files. It can also do sort order overrides, where a different order
applies to certain folders and files instead of the global order.

Feel free to suggest a rewrite of the text if needed. 🙂 I have used the
reverse configuration in an actual project and it works well:

```jsonc
// .prettierrc
{
  "plugins": ["@ianvs/prettier-plugin-sort-imports"],
  "overrides": [
    {
      "files": "please/doNot/sortThis.ts",
      "options": {
        "importOrder": [] // disabled
      }
    }
  ],
  "importOrder": [ /* global order here */ ]
  //...
}
```

Tip: The `overrides` order can come before or after the global
`importOrder`. It doesn't matter as Prettier will always apply the
override regardless of where it is in `.prettierrc`.

README.md

@@ -31,7 +31,7 @@ This project is based on [@trivago/prettier-plugin-sort-imports](https://github.
       - [4. Group type imports separately from values](#4-group-type-imports-separately-from-values)
       - [5. Group aliases with local imports](#5-group-aliases-with-local-imports)
       - [6. Enforce a blank line after top of file comments](#6-enforce-a-blank-line-after-top-of-file-comments)
-      - [7. Enforce sort order only in certain folders or files](#7-enforce-sort-order-only-in-certain-folders-or-files)
+      - [7. Enable/disable plugin or use different order in certain folders or files](#7-enabledisable-plugin-or-use-different-order-in-certain-folders-or-files)
     - [`importOrderTypeScriptVersion`](#importordertypescriptversion)
     - [`importOrderParserPlugins`](#importorderparserplugins)
   - [Prevent imports from being sorted](#prevent-imports-from-being-sorted)
@@ -333,7 +333,7 @@ import icon from '@assets/icon';
 import App from './App';
 ```
 
-##### 7. Enforce sort order only in certain folders or files
+##### 7. Enable/disable plugin or use different order in certain folders or files
 
 If you'd like to sort the imports only in a specific set of files or directories, you can disable the plugin by setting `importOrder` to an empty array, and then use Prettier's [Configuration Overrides](https://prettier.io/docs/en/configuration#configuration-overrides) to set the order for files matching a glob pattern.
 
@@ -351,6 +351,8 @@ This can also be beneficial for large projects wishing to gradually adopt a sort
 ]
 ```
 
+You can also do this in reverse, where the plugin is enabled globally, but disabled for a set of files or directories in the overrides configuration. It is also useful for setting a different sort order to use in certain files or directories instead of the global sort order.
+
 #### `importOrderTypeScriptVersion`
 
 **type**: `string`