add LICENSE, shaders, Cargo.lock, and AUR package

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

shaders/rainbow_donut.frag

@@ -0,0 +1,17 @@
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+uniform float time;
+uniform vec2 resolution;
+
+void main()
+{
+    vec2 r = resolution,
+    o = gl_FragCoord.xy - r/2.;
+    o = vec2(length(o) / r.y - .35, atan(o.y,o.x));    
+    vec4 s = .1*cos(1.6*vec4(0,1,2,3) + time + o.y + asin(sin(o.x)) * sin(time)*10.);
+    vec4 e = s.yzwx;
+    vec4 f = min(o.x-s,e-o.x);
+    gl_FragColor = dot(clamp(f*r.y,0.,1.), 80.*(s-e)) * (s-.1) - f;
+}