add Namespace to the project

Thanks for the free runners!

docs/continuous-integration.md

@@ -19,6 +19,15 @@ To enable hercules builds go to `https://hercules-ci.com/github/nix-community/$R
 
 To enable hydra builds add a new project in this [file](https://github.com/nix-community/infra/blob/master/terraform/hydra-projects.tf).
 
+#### Faster GitHub Actions
+
+[namespace](https://cloud.namespace.so) is providing us with Faster GitHub
+Actions, including ARM64 builders.
+
+Doc: <https://cloud.namespace.so/docs/features/faster-github-actions>.
+
+Limits: see the "Team plan" on <https://cloud.namespace.so/pricing>
+
 #### Cache
 
 [https://nix-community.cachix.org/](https://nix-community.cachix.org/)

docs/sponsors.md

@@ -1,7 +1,7 @@
 Thanks to all our sponsors.
 
 <!-- prettier-ignore-start -->
-|[<img src="https://raw.githubusercontent.com/cachix/docs.cachix.org/master/source/logo.png" width="200" alt="Cachix">](https://cachix.org)|[<img src="https://raw.githubusercontent.com/Gandi/.github/b1f21a402d9223c672476b41148429f538be5303/logos/black.svg" width="200" alt="Gandi">](https://www.gandi.net/)|
+|[<img src="https://raw.githubusercontent.com/cachix/docs.cachix.org/master/source/logo.png" width="200" alt="Cachix">](https://cachix.org)|[<img src="https://raw.githubusercontent.com/Gandi/.github/b1f21a402d9223c672476b41148429f538be5303/logos/black.svg" width="200" alt="Gandi">](https://www.gandi.net/)|[<img src="Logo_namespace_filled_lightbg.png" width="200" alt="Namespace">](https://cloud.namespace.so)|
-|:-:|:-:|
+|:-:|:-:|:-:|
-|Cachix provides us with 1TB of free cache.|Gandi provides us with a free domain <br /> and a virtual private server.|
+|Cachix provides us with 1TB of free cache.|Gandi provides us with a free domain <br /> and a virtual private server.|Namespace provides us with faster GitHub runners, including ARM64.|
 <!-- prettier-ignore-end -->