Initial public source release

Split reusable rendering and format support into vectorail-core and vectorail-gc.

apps/desktop/shaders/ui.vert

@@ -0,0 +1,9 @@
+#version 450 core
+layout (location = 0) in vec2 aPos;
+layout (location = 1) in vec2 aUv;
+out vec2 vUv;
+
+void main() {
+    vUv = aUv;
+    gl_Position = vec4(aPos, 0.0, 1.0);
+}