feat: Expo support (#260)

* Create `withVisionCamera` plugin

* Add docs for setting up Expo

* Update SETUP.mdx

* Update app.config.js

* rename config -> plugin

* Update SETUP.mdx

* add "runs with expo" badge to README

* Revert "add "runs with expo" badge to README"

This reverts commit e05a87a2354a056432af7b94060e95df37077472.

* fix `withVisionCamera` path

* remove unnecessary type docs

src/expo-plugin/withVisionCamera.ts

@@ -0,0 +1,29 @@
+import { withPlugins, AndroidConfig, ConfigPlugin, createRunOncePlugin } from '@expo/config-plugins';
+// eslint-disable-next-line @typescript-eslint/no-var-requires, @typescript-eslint/no-unsafe-assignment
+const pkg = require('../../package.json');
+
+const CAMERA_USAGE = 'Allow $(PRODUCT_NAME) to access your camera';
+const MICROPHONE_USAGE = 'Allow $(PRODUCT_NAME) to access your microphone';
+
+type Props = {
+  cameraPermissionText?: string;
+  enableMicrophonePermission?: boolean;
+  microphonePermissionText?: string;
+};
+
+const withCamera: ConfigPlugin<Props> = (config, props = {}) => {
+  if (config.ios == null) config.ios = {};
+  if (config.ios.infoPlist == null) config.ios.infoPlist = {};
+  config.ios.infoPlist.NSCameraUsageDescription =
+    props.cameraPermissionText ?? (config.ios.infoPlist.NSCameraUsageDescription as string | undefined) ?? CAMERA_USAGE;
+  if (props.enableMicrophonePermission) {
+    config.ios.infoPlist.NSMicrophoneUsageDescription =
+      props.microphonePermissionText ?? (config.ios.infoPlist.NSMicrophoneUsageDescription as string | undefined) ?? MICROPHONE_USAGE;
+  }
+  const androidPermissions = ['android.permission.CAMERA'];
+  if (props.enableMicrophonePermission) androidPermissions.push('android.permission.RECORD_AUDIO');
+
+  return withPlugins(config, [[AndroidConfig.Permissions.withPermissions, androidPermissions]]);
+};
+
+export default createRunOncePlugin(withCamera, pkg.name, pkg.version);