feat(ci/cd): Set up Hydra

.hydra/jobsets.nix

@@ -0,0 +1,13 @@
+#
+# jobset example file. This file can be referenced as Nix expression
+# in a jobset configuration along with inputs for nixpkgs and the
+# repository containing this file.
+#
+{ ... }:
+let
+  # <nixpkgs> is set to the value designated by the nixpkgs input of the
+  # jobset configuration.
+  pkgs = (import <nixpkgs> {});
+in {
+  hello = pkgs.hello;
+}

.hydra/spec.json

@@ -0,0 +1,46 @@
+{
+  "zsh.nix": {
+    "enabled": 1,
+    "hidden": false,
+    "description": "ZSH flake",
+    "nixexprinput": "src",
+    "nixexprpath": ".hydra/jobsets.nix",
+    "checkinterval": 300,
+    "schedulingshares": 100,
+    "enableemail": false,
+    "enable_dynamic_run_command": false,
+    "emailoverride": "",
+    "keepnr": 3,
+    "inputs": {
+      "src": {
+        "type": "git",
+        "value": "git://forgejo.stefka.eu/jiriks74/zsh.nix.git main",
+        "emailresponsible": false 
+      },
+      "nixpkgs": { "type": "git",
+        "value": "git://github.com/NixOS/nixpkgs.git release-16.03",
+        "emailresponsible": false
+      },
+      "gitea_repo_name": {
+        "type": "string",
+        "value": "zsh.nix",
+        "emailresponsible": false
+      },
+      "gitea_repo_owner": {
+        "type": "string",
+        "value": "jiriks74",
+        "emailresponsible": false
+      },
+      "gitea_status_repo": {
+        "type": "string",
+        "value": "main",
+        "emailresponsible": false
+      },
+      "gitea_http_url": {
+        "type": "string",
+        "value": "https://forgejo.stefka.eu/",
+        "emailresponsible": false
+      }
+    }
+  }
+}