Update README.md

Author: psiddh

extension/android/README.md

@@ -32,7 +32,7 @@ The AAR file will be `extension/android/executorch_android/build/outputs/aar/exe
 If you set an environment variable `BUILD_AAR_DIR`, then the AAR will be copied to `$BUILD_AAR_DIR/executorch.aar`.
 Later, you can copy `$BUILD_AAR_DIR/executorch.aar` to your app directory to use as a library.
 
-Please see [Android building from source](https://pytorch.org/executorch/main/using-executorch-android#building-from-source) for details
+Please see [Android building from source](https://pytorch.org/executorch/main/using-executorch-android#building-from-source) for details.
 
 ## Test