Add run `gulp build` clarification
Add run `gulp build` clarification

It seems like this small step was missing in the docs. Doesn't seem to warrant any sort of change in the build steps, but documenting it would be helpful for people trying out the project.
AquestTechnologies/early-landing-page,niftylettuce/gulp-aws-splash,niftylettuce/gulp-aws-splash,AquestTechnologies/early-landing-page