Kickstart a new rewrite of the raidillon engine

Endless refactors, refactor everyday, refactor relentlessly, refactor
every morning, every day, every hour.

raidillon_platform/src/platform.rs

@@ -0,0 +1,5 @@
+
+pub trait Platform {
+    /// Initialize platform.
+    fn initialize(title: String, width: u32, height: u32) -> Self;
+}