I would not use the Q&A system for that. It is allowed with some limitations. From our FAQ
May I promote products or websites I am affiliated with here?
Be careful, because the community frowns on overt self-promotion and tends to vote it down and flag it as spam. Post good, relevant answers, and if some (but not all) happen to be about your product or website, so be it. However, you must disclose your affiliation in your answers.
If a huge percentage of your posts include a mention of your product or website, you're probably here for the wrong reasons. Our advertising rates are quite reasonable; contact our ad sales team for details. We also offer free community promotion ads for open source projects and non-profit organizations.
But as a mod I can predict you will get spam flags very soon – often too soon.
There are alternatives:
You can put almost anything into your profile. Yes, even bold promotion. Images, 500 links … whatever. It should be safe for work though.
Create an image and propose a community ad. Open source plugins are welcome here explicitly. If your proposal reaches a score of 6 your image with the link will be displayed in the sidebar of our main site.