break: migrate back to bare-metal (and ansible)

- remove docker-compose.yml
- add ansible playbook for k3s and argocd deployment
- update renovate custom manager for k3s version
- update README.md with new instructions

🤖

.renovaterc.json

@@ -4,6 +4,18 @@
     "local>infrastructure/renovate-config"
   ],
   "customManagers": [
+    {
+      "customType": "regex",
+      "description": "k3s",
+      "fileMatch": [
+        "playbook\\.yml"
+      ],
+      "matchStrings": [
+        "\\s+k3s_version:\\s(?<currentValue>.*)"
+      ],
+      "depNameTemplate": "k3s-io/k3s",
+      "datasourceTemplate": "github-releases"
+    },
     {
       "customType": "regex",
       "description": "ArgoCD",