json.patch: update docs to include behavior with sets

Fixes #5328

Signed-off-by: Anders Eknert <anders@eknert.com>

ast/builtins.go

@@ -1477,7 +1477,9 @@ var JSONRemove = &Builtin{
 var JSONPatch = &Builtin{
 	Name: "json.patch",
 	Description: "Patches an object according to RFC6902. " +
-		"For example: `json.patch({\"a\": {\"foo\": 1}}, [{\"op\": \"add\", \"path\": \"/a/bar\", \"value\": 2}])` results in `{\"a\": {\"foo\": 1, \"bar\": 2}`.  The patches are applied atomically: if any of them fails, the result will be undefined.",
+		"For example: `json.patch({\"a\": {\"foo\": 1}}, [{\"op\": \"add\", \"path\": \"/a/bar\", \"value\": 2}])` results in `{\"a\": {\"foo\": 1, \"bar\": 2}`. " +
+		"The patches are applied atomically: if any of them fails, the result will be undefined. " +
+		"Additionally works on sets, where a value contained in the set is considered to be its path.",
 	Decl: types.NewFunction(
 		types.Args(
 			types.Named("object", types.A), // TODO(sr): types.A?

builtin_metadata.json

@@ -7568,7 +7568,7 @@
       "v0.46.1",
       "edge"
     ],
-    "description": "Patches an object according to RFC6902. For example: `json.patch({\"a\": {\"foo\": 1}}, [{\"op\": \"add\", \"path\": \"/a/bar\", \"value\": 2}])` results in `{\"a\": {\"foo\": 1, \"bar\": 2}`.  The patches are applied atomically: if any of them fails, the result will be undefined.",
+    "description": "Patches an object according to RFC6902. For example: `json.patch({\"a\": {\"foo\": 1}}, [{\"op\": \"add\", \"path\": \"/a/bar\", \"value\": 2}])` results in `{\"a\": {\"foo\": 1, \"bar\": 2}`. The patches are applied atomically: if any of them fails, the result will be undefined. Additionally works on sets, where a value contained in the set is considered to be its path.",
     "introduced": "v0.25.0",
     "result": {
       "description": "result obtained after consecutively applying all patch operations in `patches`",