Include linking instructions from RNNArch repo

Author: lindboe

docs/the-new-architecture/pillars-turbomodule.md

@@ -609,3 +609,51 @@ First, to enable the **New Architecture**:
 1. Open the `android/gradle.properties` file
 2. Scroll down to the end of the file and switch the `newArchEnabled` property from `false` to `true`.
 
+Then, to manually link your new TurboModule:
+
+1. Open the `NewArchitecture/android/app/build.gradle` file and update the file as it follows:
+    ```diff
+        "PROJECT_BUILD_DIR=$buildDir",
+        "REACT_ANDROID_DIR=$rootDir/../node_modules/react-native/ReactAndroid",
+    -   "REACT_ANDROID_BUILD_DIR=$rootDir/../node_modules/react-native/ReactAndroid/build"
+    +   "REACT_ANDROID_BUILD_DIR=$rootDir/../node_modules/react-native/ReactAndroid/build",
+    +   "NODE_MODULES_DIR=$rootDir/../node_modules/"
+        cFlags "-Wall", "-Werror", "-fexceptions", "-frtti", "-DWITH_INSPECTOR=1"
+        cppFlags "-std=c++17"
+    ```
+1. Open the `NewArchitecture/android/app/src/main/jni/Android.mk` file and update the file as it follows:
+    ```diff
+        # If you wish to add a custom TurboModule or Fabric component in your app you
+        # will have to include the following autogenerated makefile.
+        # include $(GENERATED_SRC_DIR)/codegen/jni/Android.mk
+    +
+    +   include $(NODE_MODULES_DIR)/rtn-calculator/android/build/generated/source/codegen/jni/Android.mk
+        include $(CLEAR_VARS)
+    ```
+1. In the same file above, go to the `LOCAL_SHARED_LIBRARIES` setting and add the following line:
+    ```diff
+        libreact_codegen_rncore \
+    +   libreact_codegen_RTNCalculator \
+        libreact_debug \
+    ```
+1. Open the `NewArchitecture/android/app/src/main/jni/MainApplicationModuleProvider.cpp` file and update the file as it follows:
+    1. Add the import for the calculator:
+        ```diff
+            #include <answersolver.h>
+        +   #include <RTNCalculator.h>
+        ```
+    1. Add the following check in the `MainApplicationModuleProvider` constructor:
+        ```diff
+            // auto module = samplelibrary_ModuleProvider(moduleName, params);
+            // if (module != nullptr) {
+            //    return module;
+            // }
+
+        +    auto module = RTNCalculator_ModuleProvider(moduleName, params);
+        +    if (module != nullptr) {
+        +        return module;
+        +    }
+
+            return rncore_ModuleProvider(moduleName, params);
+        }
+        ```