draft JSONPath documentation (#19580)

* JSONPath documentation

Author: taroface

src/current/_includes/v25.2/known-limitations/jsonpath-limitations.md

@@ -0,0 +1,2 @@
+- The following keywords are only accepted in lowercase: `strict`, `lax`, `exists`, `like_regex`, `flag`, `is unknown`, `to`, `last`. [#144255](https://github.com/cockroachdb/cockroach/issues/144255)
+- Comparisons involving empty arrays (e.g., `SELECT jsonb_path_query('{"a": [1], "b": []}', '$.a == $.b');`) return `null`, rather than `false` as in PostgreSQL. [#145099](https://github.com/cockroachdb/cockroach/issues/145099)

src/current/_includes/v25.2/sidebar-data/sql.json

@@ -885,6 +885,12 @@
                 "/${VERSION}/common-table-expressions.html"
               ]
             },
+            {
+              "title": "JSONPath Queries",
+              "urls": [
+                "/${VERSION}/jsonpath.html"
+              ]
+            },
             {
               "title": "Name Resolution",
               "urls": [