add meaningful descriptions including keywords (#9715)

services/amo/amo-base.js

services/amo/amo-downloads.service.js

services/amo/amo-rating.service.js

services/amo/amo-users.service.js

services/amo/amo-version.service.js

services/bit/bit-components.service.js

services/coincap/coincap-base.js

services/coincap/coincap-changepercent24hr.service.js

services/coincap/coincap-priceusd.service.js

services/coincap/coincap-rank.service.js

services/conan/conan-version.service.js

services/cpan/cpan-license.service.js

services/cpan/cpan-version.service.js

services/cpan/cpan.js