Add project showcase page

Author: kabilar

src/projects/index.md

@@ -0,0 +1,23 @@
+# Project Showcase
+
+<div class="grid cards" markdown>
+
+-   **Select projects supported by DataJoint software**
+
+     ---
+
+     [:octicons-arrow-right-24: Catalog](https://catalog.datajoint.io)
+
+-   **Research teams supported by DataJoint software**
+
+     ---
+
+     [:octicons-arrow-right-24: Teams](teams.md)
+
+-   **Publications supported by DataJoint software**
+
+     ---
+
+     [:octicons-arrow-right-24: Publications](./publications/)
+
+</div>