Modification:

- adjust the description text of what helmholtz cloud does.
- upload two images and one of them is used as the background
   image of the site landing page.
- add arrow to indicate that user can scroll down the page
   and remove the scroll down indicator when the user scroll
   down.
- change the sign-in button to go-to-service button. And add
   a little bit of styling to the button for meet the cooperate
   design requirement.

Result:

Target: master