update documentation  to address gulp 4 update
update documentation  to address gulp 4 update

Altinn/DesignSystem,pcvonz/pattern_lab_playground,pattern-lab/edition-node-gulp,patternfly/patternfly-atomic,pcvonz/pattern_lab_playground,bsmart/pdxr-pl,Altinn/DesignSystem,pcvonz/pattern_lab_playground,patternfly/patternfly-atomic,KatieMFritz/safs-patternlab-node-gulp-twig,bsmart/pdxr-pl,KatieMFritz/safs-patternlab-node-gulp-twig,pattern-lab/edition-node-gulp