Adds hosting provider Zoondka logo and thank you text

[bgirardot]

No description provided.

[pgiraud]

Hi @bgirardot
2 minor comments about this pull request:

• the wording "Software hosting" sound incorrect to me. "Software" is not hosted actually. One instance of the application is. I think "Hosting" makes more sense.
• this new section in the about page is specific to HOT. The tasking manager is an opensource software. It can be hosted anywhere. Ideally the new "hosting" section should be added as a new macro in the custom template. In order for others to change or remove it if they want.

Otherwise, I think it's a good idea to thank the Zoondka team.