See the contributing docs
Note: We are regularly asked whether we can add or take away features. If a change is good enough to have a positive impact on all users, we are happy to consider it.
If not, generator-gulp-webapp is fork-friendly and you can always maintain a custom version which you npm install && npm link to continue using via yo gulp-webapp or a name of your choosing.
We frequently get issues where people modified something after they finished scaffolding and things weren't working properly. These are classified as support questions; they are related to this generator, but not something we did wrong. It's best to ask those on Stack Overflow with tags #yeoman and #gulp instead of opening an issue here. You can also ask questions in our IRC channel (#yeoman on Freenode).
If the issue has already been opened before it turned out to be a support question, feel free to paste the link to the Stack Overflow question, so we can answer it.