README.md: reorganise and add services

README.md

@@ -6,11 +6,24 @@ Welcome to the Nix Community infrastructure project. This project holds all the
 
 ### `Community builder` - build01.nix-community.org
 
-We also provide one x86 hetzner build machine as a public remote builder for the nix community, see [here](roles/builder/README.md) for more information.
+We provide an x86 build machine as a public remote builder for the nix community, this machine also has an aarch64 machine configured as its own remote builder.
 
-### `Hydra` - https://hydra.nix-community.org
+See [here](roles/builder/README.md) for more information.
 
-If you want to build your project in our hydra, add a new project in this [file](terraform/hydra-projects.tf).
+### `Continuous integration`
+
+We provide x86 and aarch64 linux CI via these systems:
+
+- `Hercules` - https://hercules-ci.com/github/nix-community
+
+- `Hydra` - https://hydra.nix-community.org
+  - To enable hydra builds add a new project in this [file](terraform/hydra-projects.tf).
+
+### `Cache` - https://nix-community.cachix.org/
+
+All of the above CI builds are pushed to the cache.
+
+Thanks to Cachix for sponsoring our binary cache!
 
 ### `Search` - https://search.nix-community.org
 
@@ -25,6 +38,8 @@ DNS is managed by terraform in this [file](terraform/cloudflare_nix-community_or
 * Docs: https://ryantm.github.io/nixpkgs-update
 * Logs: https://r.ryantm.com/log/
 
+### `nur-update`
+
 ## Support
 
 If you hit any issues, ping us on Matrix in the [nix-community](https://matrix.to/#/#nix-community:nixos.org) room (see the admin list below) or create an issue here:
@@ -51,9 +66,3 @@ As PRs from forks don't have automatic CI checks, admins can test PRs by posting
 ## Hosts
 
 See [HOSTS.md](HOSTS.md), this file also contains deployment details.
-
-## Cache
-
-All the builds on these machines are pushed to https://nix-community.cachix.org/
-
-Thanks to Cachix for sponsoring our binary cache!