feat(adopters): add sendinblue

Co-authored-by: kuldeep-sib <62245141+kuldeep-sib@users.noreply.github.com>

Signed-off-by: TANGUY Antoine (SIB) <tanguyantoine@users.noreply.github.com>

ADOPTERS.md

@@ -132,3 +132,4 @@ _If you're using Backstage in your organization, please try to add your company
 |[The Warehouse Group](https://www.thewarehouse.co.nz)|[Matt Law](mailto:matt.law@thewarehouse.co.nz)|Backstage enables us to bootstrap our middleware environment of new services for our Dev teams in a matter of seconds. CI, CD, testing, logging, deployments are all taken care of to get them up and running in less than 60 seconds.
 | [Tink](https://tink.com/)                                                   | [Sebastian Olsson](https://github.com/Sebelino), [Błażej Szum](https://github.com/blazejszumtink), [Anders Eurenius Runvald](https://github.com/anders-er-at-tink)                                                                                               | Internal developer portal which provides templates for creating new Java or Go microservices seamlessly. Also includes a tech radar and a visualization of our CD pipeline.                                                                                                                                                                          |
 | [Brandwatch](https://brandwatch.com)| [Stefan Buck](https://github.com/stefanbuck) | Our primary focus is on the service catalog. Backstage is replacing our homemade service catalog. The switch was quite simple due to the catalog processor API.
+| [Sendinblue](https://engineering.sendinblue.com/)| [Tanguy Antoine](mailto:antoine.tanguy@sendinblue.com) | Helps us drive the change at scale. Puts light on services, resources, and dependencies. One tool that rules them all through plugins we created for that purpose. We are aiming to put Backstage at the center of every developer's work (Actionable items, Debugging, Monitoring, Provisioning, etc...) to improve their happiness  |