Add Dex to the sandbox

Signed-off-by: Chris Aniszczyk <[email protected]>

docs/projects.md

@@ -50,6 +50,7 @@
 [Volcano](https://volcano.sh)|Liz Rice, Sheng Liang, Alena Prokharchyk|[11/6/19](https://github.com/cncf/toc/pull/318) - [SIG Runtime](https://github.com/cncf/sig-runtime/blob/master/recommendations/sandbox/volcano.md)|[4/10/20](https://github.com/volcano-sh/)|Sandbox
 [BFE](https://www.bfe-networks.net)|TOC Vote|[5/26/20](https://github.com/cncf/toc/pull/453)|[6/23/20](https://github.com/bfenetworks/bfe)|Sandbox
 [Crossplane](https://www.crossplane.io)|TOC Vote|[5/26/20](https://github.com/cncf/toc/pull/454)|[6/23/20](https://github.com/crossplane/crossplane)|Sandbox
+[Dex](https://github.com/dexidp/dex)|TOC Vote|[3/4/20](https://github.com/cncf/toc/pull/379)|[6/23/20](https://github.com/dexidp/dex)|Sandbox
 
 ## Graduated Projects
 **Project**|**Sponsor**|**TOC Deck**|**Graduated**|**Maturity Level**