Add a credit for IPAC (#672)

* Add a credit for IPAC

closes #671

Co-authored-by: Brigitta Sipőcz <[email protected]>

Author: hamogu

credits.html

@@ -270,6 +270,9 @@ <h3 id="cxc">Chandra X-ray Center (CXC)</h3>
 The CXC has supported multiple staff members to work on the Astropy project,
 equivalent to more than 5 person-years since the start of the project.
 
+<h3 id="CaltecIPAC">IPAC at CalTech</h3>
+The NASA/IPAC Infrared Science Archive (IRSA) at Caltech curates and serves the science products and documentation for many space- and ground-based observatories. In our work, we have benefitted from the Astropy project, and have been committed to sharing our solutions back to the project to benefit the broader community. Most of our effort has gone into the astroquery, pyvo, and the core libraries.
+
 <h3 id="numfocus">NumFOCUS</h3>
 We wish to express gratitude to the NumFocus Organization for providing the
 organizational support to grow Astropy into the role of a community-leading