docs: Add readOnly to config docs

README.md

@@ -111,7 +111,8 @@ export const storage = new MMKV({
   id: `user-${userId}-storage`,
   path: `${USER_DIRECTORY}/storage`,
   encryptionKey: 'hunter2',
-  mode: Mode.MULTI_PROCESS
+  mode: Mode.MULTI_PROCESS,
+  readOnly: false
 })
 ```
 
@@ -123,6 +124,7 @@ The following values can be configured:
 * `path`: The MMKV instance's root path. By default, MMKV stores file inside `$(Documents)/mmkv/`. You can customize MMKV's root directory on MMKV initialization (documentation: [iOS](https://github.com/Tencent/MMKV/wiki/iOS_advance#customize-location) / [Android](https://github.com/Tencent/MMKV/wiki/android_advance#customize-location))
 * `encryptionKey`: The MMKV instance's encryption/decryption key. By default, MMKV stores all key-values in plain text on file, relying on iOS's/Android's sandbox to make sure the file is encrypted. Should you worry about information leaking, you can choose to encrypt MMKV. (documentation: [iOS](https://github.com/Tencent/MMKV/wiki/iOS_advance#encryption) / [Android](https://github.com/Tencent/MMKV/wiki/android_advance#encryption))
 * `mode`: The MMKV's process behaviour - when set to `MULTI_PROCESS`, the MMKV instance will assume data can be changed from the outside (e.g. App Clips, Extensions or App Groups).
+* `readOnly`: Whether this MMKV instance should be in read-only mode. This is typically more efficient and avoids unwanted writes to the data if not needed. Any call to `set(..)` will throw.
 
 ### Set