Added Shader class, default shaders

assets/shaders/default.frag.glsl

@@ -0,0 +1,8 @@
+#version 330 core
+
+in vec4 fColour;
+out vec4 colour;
+
+void main() {
+  colour = fColour;
+}

assets/shaders/default.vert.glsl

@@ -0,0 +1,11 @@
+#version 330 core
+
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec4 aColour;
+
+out vec4 fColour;
+
+void main() {
+  fColour = aColour;
+  gl_Position = vec4(aPos, 1.0);
+}