chore(kontemplate): Prepare kontemplate for depot-merge

This merge will not yet include moving over to buildGo.nix, as support
for testing and such is not present in that library yet.

ops/kontemplate/context/testdata/merging/context.yaml

@@ -0,0 +1,15 @@
+# This context file is intended to test the merge hierarchy of
+# variables defined at different levels.
+---
+context: merging.in.kontemplate.works
+global:
+  globalVar: globalVar
+  includeVar: should be overridden (global)
+  cliVar: should be overridden (global)
+import:
+  - import-vars.yaml
+include:
+  - name: resource
+    values:
+      includeVar: includeVar
+      cliVar: should be overridden (include)