Implement cool shader effects

[azulus]

Star: https://www.shadertoy.com/view/4dXGR4
Stars: https://www.shadertoy.com/view/XlfGRj
Gargantua: https://www.shadertoy.com/view/lstSRS
Galaxy: https://www.shadertoy.com/view/Xsl3zX
Stars 2: https://www.shadertoy.com/view/Mll3zj
Zooming Starfield: https://www.shadertoy.com/view/XtBSWt

Rainbow laser: https://www.shadertoy.com/view/XtBXW3
Electro: https://www.shadertoy.com/view/4scGWj