fix incorrect info about custom data and fix prototype link

[zebapy]

Either the source files that have panini preconfigured need to be updated to add the data: 'src/data' path or the documentation should reflect the requirement.

Also the prototyping link was dead. I'm not sure if this is the correct new link but I've added it for now.

Edited Remade PR as requested by @rafibomb in #492

[zebapy]

@rafibomb do you think the boilerplate/template should just include the src/data path to begin with?

[rafibomb]

Good question! Let's see what @kball thinks

[kball]

@zebapy I think it would make sense to have data in there by default with a sample/empty data file there as an example.

[rafibomb]

Thanks @kball
@zebapy Is that something you can add to this PR? Would love to document this better in panini!

[zebapy]

@rafibomb I can add that, sure. That would be done in the template project, right?

[rafibomb]

Yes! The foundation-emails-template is what creates the project structure! Can you add it there too and the docs here can describe it.

[zebapy]

@rafibomb There's a PR open for custom data. I'll update this PR to remove the doc change and leave the link fix. foundation/foundation-emails-template#20

[tdhartwick]

Thanks @zebapy! Merged in the updated Panini copy.

[Lulubbz]

Ohk