chore: Significantly restructure folder layout

This moves the various projects from "type-based" folders (such as
"services" or "tools") into more appropriate semantic folders (such as
"nix", "ops" or "web").

Deprecated projects (nixcon-demo & gotest) which only existed for
testing/demonstration purposes have been removed.

(Note: *all* builds are broken with this commit)

ops/infra/kubernetes/primary-cluster.yaml

@@ -0,0 +1,38 @@
+# Kontemplate configuration for the primary GKE cluster in the project
+# 'tazjins-infrastructure'.
+---
+context: gke_tazjins-infrastructure_europe-north1_tazjin-cluster
+include:
+  # SSL certificates (provisioned by Google)
+  - name: tazj-in-cert
+    path: https-cert
+    values:
+      domain: tazj.in
+  - name: www-tazj-in-cert
+    path: https-cert
+    values:
+      domain: www.tazj.in
+  - name: git-tazj-in-cert
+    path: https-cert
+    values:
+      domain: git.tazj.in
+  - name: oslo-pub-cert
+    path: https-cert
+    values:
+      domain: oslo.pub
+
+  # Services
+  - name: nixery
+    values:
+      port: 8080
+      version: xkm36vrbcnzxdccybzdrx4qzfcfqfrhg
+      bucket: tazjins-data
+      account: nixery@tazjins-infrastructure.iam.gserviceaccount.com
+      repo: ssh://tazjin@gmail.com@source.developers.google.com:2022/p/tazjins-infrastructure/r/depot
+      popularity: 'popularity-nixos-unstable-3140fa89c51233397f496f49014f6b23216667c2.json'
+  - name: tazblog
+  - name: cgit
+  - name: https-lb
+  - name: nginx
+    values:
+      version: a349d5e9145ae9a6c89f62ec631f01fb180de546