docs: update concepts page
docs: update concepts page

Related: https://github.com/driftyco/ionic-site/issues/314

driftyco/ionic-site,driftyco/ionic-site,ionic-team/ionic-site,ionic-team/ionic-site,ionic-team/ionic-site,driftyco/ionic-site,driftyco/ionic-site,ionic-team/ionic-site,driftyco/ionic-site