Typo in parts with imports specification

[sgrekhov]

language/working/parts-with-imports/feature-specification.md

Line 286 in 70e9abc

**It's a '** if any file declares an import prefix with the

I believe there should be "It's a compile-time error...". The same is for line 302. There should be "compile-time error" instead of '.

[lrhn]

Yep, should be fixed on the PR I have for removing conditional parts and cleaning up some other things.