[#57958020] Implement new design header on blog crowdint

* Add new assets
* Add new basic styles for header
WIP new header
[#57958020] New header design for blog crowdint
[#57958020] New header design
[#57958020] New header design

* Add tip under share knowledge
* Add tip under share knowledge menu
Merge pull request #6 from crowdint/new_image_header

New image header