feat: Remove deprecated articles (#85)

These were already "deprecated"/"outdated" years ago. Now they are
relics of the past. Might as well remove the entire section.

README.md

@@ -79,27 +79,6 @@
 
 - [How to build a real-time multiplayer game with Flutter Flame](https://supabase.com/blog/flutter-real-time-multiplayer-game) - Using Flutter, Flame, and Supabase's real-time features to build a real-time multiplayer shooting game. By [Tyler Shukert](https://twitter.com/dshukertjr).
 
-### Deprecated Articles & Tutorials
-
-The tutorials in this section were written a long time ago and you'll have to do a lot of changes
-to get their code to run with any up-to-date version of Flame.
-
-#### Beginner Tutorial Series by [Alekhin](https://github.com/japalekhin)
-
-- [Create a Mobile Game with Flutter and Flame - Beginner Tutorial (Introduction)](https://jap.alekhin.io/create-mobile-game-flutter-flame-beginner-tutorial)
-- [2D Casual Mobile Game Tutorial - Step by Step with Flame and Flutter (Part 1 of 5)](https://jap.alekhin.io/2d-casual-mobile-game-tutorial-flame-flutter-part-1)
-- [Game Graphics and Animation Tutorial - Step by Step with Flame and Flutter (Part 2 of 5)](https://jap.alekhin.io/game-graphics-and-animation-tutorial-flame-flutter-part-2)
-- [Views and Dialog Boxes Tutorial - Step by Step with Flame and Flutter (Part 3 of 5)](https://jap.alekhin.io/views-dialog-boxes-tutorial-flame-flutter-part-3)
-- [Scoring, Storage, and Sound Tutorial - Step by Step with Flame and Flutter (Part 4 of 5)](https://jap.alekhin.io/scoring-storage-sound-tutorial-flame-flutter-part-4)
-- [Game Finishing and Packaging Tutorial - Step by Step with Flame and Flutter (Part 5 of 5)](https://jap.alekhin.io/game-finishing-packaging-tutorial-flame-flutter-part-5)
-
-<!--lint ignore double-link-->
-#### Articles by [Fireslime](https://fireslime.xyz/)
-
-<!--lint ignore double-link-->
-- [Creating a virtual controller with Stack on Flame](https://fireslime.xyz/articles/20190902_Flame_Virtual_Controller_With_Stack.html)
-- [Basic Camera usage on Flame](https://fireslime.xyz/articles/20190911_Basic_Camera_Usage_In_Flame.html)
-
 ### Examples
 
 - [Maze generator](https://github.com/Dannark/FlameExamples) - List of algorithm examples to solve problems like Maze generation and more. By [Dannark](https://github.com/Dannark/)