Update jQuery/bootstrap and use single copy #5804
Description
There are two versions of jQuery included (3 if you include docs_theme):
% find rest_framework docs_theme -iname '*jquery*js*'
rest_framework/static/rest_framework/docs/css/jquery.json-view.min.css
rest_framework/static/rest_framework/docs/js/jquery-1.10.2.min.js
rest_framework/static/rest_framework/docs/js/jquery.json-view.min.js
rest_framework/static/rest_framework/js/jquery-1.12.4.min.js
docs_theme/js/jquery-1.8.1-min.js
It would be good to only have one copy included, and update it then - to fix e.g. an existing vulnerability (https://snyk.io/vuln/npm:jquery:20150627).