This change adds the `loadShader` and `shader` function, to be used like this:
```strudel
await loadShader`
// The modulation targets
uniform float iColor;
void mainImage( out vec4 fragColor, in vec2 fragCoord ) {
vec2 uv = fragCoord / iResolution.xy;
vec3 col = 0.5 + 0.5*cos(iColor+uv.xyx+vec3(0,2,4));
fragColor = vec4(col, 0);
}
`
$: s("bd").shader({uniform: 'iColor'})
```