Edit to content.json under [search]

Added image to “explore” and teaching kit to “teach” under Search
section. Fixed Aki multimedia array issue (I think? First time i’m
adding an image like this.)
Edit to content.json under [search] #2

with comma.
Merge pull request #993 from keyboardkat/search-change-test

Bug 1063035 - Add new media and content to [Web Literacy: Search] page