Prefix auto-generated image filenames with diag-

[danyill]

As pointed out in #48, asciidoctor-diagram prefixes auto-generated image filenames with diag-

I'd be keen to have the diag- prefix in asciidoctor-kroki as a way of namespacing the generated images which don't have an explicit filename (for instance useful if one wished to include in a .gitignore).

[ggrossetie]

I'd be keen to have the diag- prefix in asciidoctor-kroki as a way of namespacing the generated images which don't have an explicit filename (for instance useful if one wished to include in a .gitignore).

That's a very good point and it will get us one step closer to Asciidoctor diagram 👍

[anb0s]

May be it would be also good to have it configured? E.g. kroki-fetch-diagram-prefix default set to diag- ? Only for auto-generated file-names... so i would set it to generated- or if possible generated/ to have it in an imgdir subfolder.