Draft triangle pipeline in iced_glow

glow/src/shader/triangle.vert

@@ -0,0 +1,13 @@
+#version 450
+
+layout(location = 0) uniform mat4 u_Transform;
+
+layout(location = 0) in vec2 i_Position;
+layout(location = 1) in vec4 i_Color;
+
+layout(location = 0) out vec4 o_Color;
+
+void main() {
+    gl_Position = u_Transform * vec4(i_Position, 0.0, 1.0);
+    o_Color = i_Color;
+}