remove redundant DECISIONS.md pointer

One-line file pointing to decisions/README.md which already exists.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.pql/pql-plan.json

@@ -1,5 +1,5 @@
 {
-  "exported_at": "2026-04-26T15:17:17Z",
+  "exported_at": "2026-04-26T16:34:55Z",
   "decisions": [
     {
       "id": "D-1",

DECISIONS.md

@@ -1 +0,0 @@
-See [`decisions/README.md`](decisions/README.md).