Manually add Sighup (#523)

### Pre-submission checklist:

*Please check each of these after submitting your pull request:*

* [ ] Are you only including a `repo_url` if your project is 100% open
source? If so, you need to pick the single best GitHub repository for
your project, not a GitHub organization.
* [ ] Is your project closed source or, if it is open source, does your
project have at least 250 GitHub stars?
* [ ] Have you picked the single best (existing) category for your
project?
* [ ] Does it follow the other guidelines from the [new
entries](https://github.com/cncf/landscape#new-entries) section?
* [ ] Have you included a URL for your SVG or added it to `hosted_logos`
and referenced it there?
* [ ] Does your logo clearly state the name of the project/product and
follow the other logo
[guidelines](https://github.com/cncf/landscape#logos)?
* [ ] Does your project/product name match the text on the logo?
* [ ] Have you verified that the Crunchbase data for your organization
is correct (including headquarters and LinkedIn)?
* [ ] ~10 minutes after opening the pull request, the CNCF-Bot will post
the URL for your staging server. Have you confirmed that it looks good
to you and then added a comment to the PR saying "LGTM"?

---------

Signed-off-by: riaan kleinhans <[email protected]>