Adding Squash (from Henix) to technology partner page

Marion Delobeaurequested to merge
mdelobeau/www-gitlab-com:squash-partners-page into master

For the contribution process and guidelines, please check Integrate with GitLab.

Checklist:

  1. Application's data added to data/applications.yml (to the end of the category)
  2. Application's logo added to source/images/applications/apps/ (optional, but recommended)
  3. Mike LeBeau's review - cc/ @mlebeau
  4. Tech writer's review

Merge request reports