docs: Add Kotlin & Swift FP plugins examples (#1902)

* chore(docs): add Kotlin FP example

* chore(docs): add Swift FP plugin

package/example/src/frame-processors/ExampleKotlinSwiftPlugin.ts

@@ -0,0 +1,17 @@
+import { VisionCameraProxy, Frame } from 'react-native-vision-camera'
+
+const plugin = VisionCameraProxy.getFrameProcessorPlugin('example_kotlin_swift_plugin')
+
+export function exampleKotlinSwiftPlugin(frame: Frame): string[] {
+  'worklet'
+
+  if (plugin == null) throw new Error('Failed to load Frame Processor Plugin "example_kotlin_swift_plugin"!')
+
+  return plugin.call(frame, {
+    someString: 'hello!',
+    someBoolean: true,
+    someNumber: 42,
+    someObject: { test: 0, second: 'test' },
+    someArray: ['another test', 5],
+  }) as string[]
+}