Add raylib build script

rlbuild

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+cmake -S raylib-src -B raylib-build -DCMAKE_INSTALL_PREFIX=raylib -DCMAKE_CONFIGURATION_TYPES=Release -DBUILD_SHARED_LIBS=ON -G "Ninja Multi-Config"
+cmake --build raylib-build --config=Release
+cmake --install raylib-build --config=Release