Adds links to new Flutter / Lottie tutorial

Author: FilledStacks

README.md

@@ -28,13 +28,15 @@ In the repo to generate the platform projects for the tutorials.
 
 ## Tutorials
 
+**055 - Lottie Splash Screen in Flutter** \[ [Video](https://youtu.be/YcUip0Y8CUg) \] \[ [Written](https://www.filledstacks.com/post/lottie-splash-screen-intro-in-flutter/) \] - A tutorial that shows you how to implement an animated splash screen using Lottie and delay the navigation until it's complete.
+
 **054 - Flutter Architecture Part 7 - Dialog Service** \[ [Video](https://youtu.be/uuyJHCxxMEY) \] \[ [Written](https://www.filledstacks.com/post/show-dialogs-without-context/) \] \[ [Source Code](https://github.com/FilledStacks/stacked-example/tree/part-7-dialog-service) \] - A complete guide to the setup of the basics for a starter stacked architecture project.
 
 **053 - Flutter Architecture Part 6 - Bottom Navigation with Stacked** \[ [Video](https://youtu.be/OBIrqm0LDaA) \] \[ [Written](https://www.filledstacks.com/post/bottom-navigation-with-stacked-architecture/) \] \[ [Source Code](https://github.com/FilledStacks/stacked-example/tree/part-6-bottom-nav) \] - A guide to implementing a bottom navigation bar using stacked.
 
 **052 - Flutter Architecture Part 5 - How to Mock - Unit Testing** \[ [Video](https://youtu.be/Kq-YMAE1ssA) \] \[ [Written](https://www.filledstacks.com/post/how-to-mock-for-unit-testing/) \] \[ [Source Code](https://github.com/FilledStacks/stacked-example/tree/part-5-mocking-unit-tests) \] - A complete guide to mocking in unit testing, how it's used for tests and what they're used for.
 
-**051 - Flutter Architecture Part 4 - How to Unit test a Unit Testing intro** \[ [Video](https://youtu.be/n21w5T3jdWE) \] \[ [Written](https://www.filledstacks.com/post/how-to-unit-test-in-flutter/) \] \[ [Source Code](https://github.com/FilledStacks/stacked-example/tree/part-4-unit-testing-1) \] - An intro to unit testing and how to set it up in Flutter. 
+**051 - Flutter Architecture Part 4 - How to Unit test a Unit Testing intro** \[ [Video](https://youtu.be/n21w5T3jdWE) \] \[ [Written](https://www.filledstacks.com/post/how-to-unit-test-in-flutter/) \] \[ [Source Code](https://github.com/FilledStacks/stacked-example/tree/part-4-unit-testing-1) \] - An intro to unit testing and how to set it up in Flutter.
 
 **050 - Flutter Architecture Part 3 - Flutter Services** \[ [Video](https://youtu.be/UoZQS1bkNTw) \] \[ [Written](https://www.filledstacks.com/post/services-in-code-and-how-to-use-them-in-flutter/) \] \[ [Source Code](https://github.com/FilledStacks/stacked-example/tree/part-3-services) \] - A complete guide on services, service classes, what they are used for and how to use them.