Clarify copy_without_render

[cdlm]

It's not clear what copy_without_render will be matched against and how.

Judging from the source code the glob pattern is used as-is, against the "real" path (fully resolved in the filesystem? relative to output directory?) of the destination where the template file would be copied to, but:

• does that include the output directory (--output-dir CLI option) ?
• it doesn't seem like template variables are expanded in the glob, which makes it impossible to match individual files when those have templated names (say I need to render most files in template/there/*.html except for template/there/{{name}}.html)
• what about matching template-relative paths (so, the source files)?

[Keats]

1. Not sure, would have to test it
2. Correct, they are not templated right now it could be added
3. Ideally that's how it would work