Add terraform-provider-kea repository

Provisions the Gitea repo for the Terraform provider wrapping the
kea-operator KeaAPI (subnets + client classes).

Claude-Session: https://claude.ai/code/session_01JUoARVdmhxKQHyyyp1pxeT

config/git.unkin.net/unkin/repository/terraform-provider-kea.yaml

@@ -0,0 +1,14 @@
+description: "Terraform provider for the kea-operator KeaAPI: manage Kea DHCP subnets and PXE client classes."
+private: false
+default_branch: "main"
+default_delete_branch_after_merge: true
+default_merge_style: "squash"
+branch_protection:
+  - rule_name: "main"
+    enable_push: false
+    status_check_contexts:
+      - "ci/woodpecker/pr/pre-commit"
+      - "ci/woodpecker/pr/build"
+      - "ci/woodpecker/pr/test"
+    approval_whitelist_users:
+      - "benvin"