Remove Gratipay and Flattr from sidebar of docs

Change python-pybabel to python-babel in package requirements

Closes #1147

update search api with params and description on syntax

add missing screenshot of admin page

blog: add post about searx-admin

update documentation

add first blog entry on python3 support

Corrected spelling of ads in user/own-instance.html

[doc] bump version to 0.11 && rewrite Translation page

fix nginx section of installation page

documentation update && new page

add "How to protect an instance" section

docs: time_range search param, embed