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

* chore(docs): add Kotlin FP example

* chore(docs): add Swift FP plugin

package/example/android/app/build.gradle

@@ -1,5 +1,6 @@
 apply plugin: "com.android.application"
 apply plugin: "com.facebook.react"
+apply plugin: "kotlin-android"
 
 import com.android.build.OutputFile
 

package/example/android/app/src/main/java/com/mrousavy/camera/example/ExampleKotlinFrameProcessorPlugin.kt

@@ -0,0 +1,35 @@
+package com.mrousavy.camera.example
+
+import android.util.Log
+import com.mrousavy.camera.frameprocessor.Frame
+import com.mrousavy.camera.frameprocessor.FrameProcessorPlugin
+
+class ExampleKotlinFrameProcessorPlugin: FrameProcessorPlugin() {
+    override fun callback(frame: Frame, params: Map<String, Any>?): Any? {
+        if (params == null) {
+            return null
+        }
+
+        val image = frame.image
+        Log.d(
+            "ExampleKotlinPlugin",
+            image.width.toString() + " x " + image.height + " Image with format #" + image.format + ". Logging " + params.size + " parameters:"
+        )
+
+        for (key in params.keys) {
+            val value = params[key]
+            Log.d("ExampleKotlinPlugin", "  -> " + if (value == null) "(null)" else value.toString() + " (" + value.javaClass.name + ")")
+        }
+
+        return hashMapOf<String, Any>(
+            "example_str" to "KotlinTest",
+            "example_bool" to false,
+            "example_double" to 6.7,
+            "example_array" to arrayListOf<Any>(
+                "Good bye",
+                false,
+                21.37
+            )
+        )
+    }
+}

package/example/android/app/src/main/java/com/mrousavy/camera/example/MainApplication.java

@@ -66,5 +66,6 @@ public class MainApplication extends Application implements ReactApplication {
     }
 
     FrameProcessorPluginRegistry.addFrameProcessorPlugin("example_plugin", options -> new ExampleFrameProcessorPlugin());
+    FrameProcessorPluginRegistry.addFrameProcessorPlugin("example_kotlin_swift_plugin", options -> new ExampleKotlinFrameProcessorPlugin());
   }
 }

package/example/android/build.gradle

@@ -15,5 +15,6 @@ buildscript {
     dependencies {
         classpath('com.android.tools.build:gradle:7.4.1')
         classpath("com.facebook.react:react-native-gradle-plugin")
+        classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:1.7.22")
     }
 }