Implemented loading shaders from file.

assets/shaders/glsl/triangle.vert

@@ -0,0 +1,12 @@
+#version 460
+
+const vec2 vertices[3] = vec2[3](
+    vec2(-0.5, 0.5),
+    vec2( 0.5, 0.5),
+    vec2( 0.0, -0.5)
+);
+
+void main()
+{
+    gl_Position = vec4(vertices[gl_VertexIndex], 0.0, 1.0);
+}