Update networking.md to list ACI CNI plugin (#6367)

* Update networking.md

* Update networking.md

Author: anvega

docs/concepts/cluster-administration/networking.md

@@ -103,6 +103,11 @@ as an introduction to various technologies and serves as a jumping-off point.
 The following networking options are sorted alphabetically - the order does not
 imply any preferential status.
 
+### ACI
+
+[Cisco Application Centric Infrastructure](https://www.cisco.com/c/en/us/solutions/data-center-virtualization/application-centric-infrastructure/index.html) offers an integrated overlay and underlay SDN solution that supports containers, virtual machines, and bare metal servers. [ACI](https://www.github.com/noironetworks/aci-containers) provides container networking integration for ACI. An overview of the integration is provided [here](https://www.cisco.com/c/dam/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/solution-overview-c22-739493.pdf).
+ 
+
 ### Cilium
 
 [Cilium](https://github.com/cilium/cilium) is open source software for