Upnode Alt DA draft

Author: upnodedev

pages/builders/chain-operators/features/alt-da-mode.mdx

@@ -46,6 +46,7 @@ You should use at least the following compatible op\* versions when running your
   *   Avail's docs on how to run the [AvailDA DA Server](https://docs.availproject.org/docs/build-with-avail/Optimium/op-stack/op-stack#setup-avail-da-server)
   *   0gDA's docs on how to run the [0gDA DA Server](https://github.com/0glabs/0g-da-op-plasma)
   *   Near DA's docs on how to run the [Near DA Server](https://github.com/Nuffle-Labs/data-availability/blob/84b484de98f58a91bf12c8abe8df27f5e753f63a/docs/OP-Alt-DA.md)
+  *   Upnode has provided an [Alt DA server for local filestore, IPFS and Arweave using Keccak256 commitment](https://github.com/upnodedev/op-alt-da)
 
   ### Configure your `op-node`