update search box on homepage to have default value
update search box on homepage to have default value


Former-commit-id: 9adbd0494a8b6b1671a0d21628e0d2fbb5f152f7
julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine,julie-sullivan/phytomine