autodetect shader uniforms

[KrabCode]

annotations and regex

[KrabCode]

things to figure out:

• how to register a shader as auto-detectable, perhaps a separate public call to ShaderReloader with the path?
• what will the annotations look like, perhaps #slider=3 do they include ranges?
• do these new controls belong into a new nested folder? what will be the folder name?
• can we represent all the control elements as a uniform? probably yes
• good errors for type mismatches, like a float uniform trying to consume a #gradient or #color