[ZA] Mention fixing malformed slugs in docs
[ZA] Mention fixing malformed slugs in docs

Without this some of the slugs will be incorrect and won't be matched by
the application routes.

geoffkilpin/pombola,hzj123/56th,patricmutwiri/pombola,geoffkilpin/pombola,hzj123/56th,geoffkilpin/pombola,mysociety/pombola,mysociety/pombola,hzj123/56th,ken-muturi/pombola,geoffkilpin/pombola,mysociety/pombola,patricmutwiri/pombola,patricmutwiri/pombola,hzj123/56th,mysociety/pombola,geoffkilpin/pombola,hzj123/56th,mysociety/pombola,patricmutwiri/pombola,ken-muturi/pombola,hzj123/56th,ken-muturi/pombola,patricmutwiri/pombola,ken-muturi/pombola,ken-muturi/pombola,patricmutwiri/pombola,geoffkilpin/pombola,ken-muturi/pombola,mysociety/pombola