De-emphasize deprecated |-operator in docs and examples

docs/changelog.md

@@ -22,9 +22,8 @@ Language:
 
  * Add [unpack](syntax.md#unpack): `..` and `...` syntax that can be used inside
    lists, sets, and dicts to unpack one collection into another.
- * Unpack can be used to express dict and set unions without the need for
-   the `|` operator. As such, the `|` operator is now deprecated, and will
-   be removed in a future version.
+ * The `|` operator is now deprecated, and will be removed in a future version.
+   The new unpack feature can be used to express dict and set unions instead.
  * [Assertions](syntax.md#assertions) now use a `:` to separate the condition
    and the message: `assert cond: "message";` rather than
    `assert cond, "message";`. For compatibility, <abbr>RCL</abbr> still accepts

docs/syntax.md

@@ -290,7 +290,6 @@ Binary operators that operate between two expressions, e.g. `x and y`:
 | `<=`     | Less than or equal to |
 | `>`      | Greater than |
 | `>=`     | Greater than or equal to |
-| `|`      | Set or dict union, right-biased for dicts |
 | `+`      | Numeric addition |
 | `-`      | Numeric subtraction |
 | `*`      | Numeric multiplication |

docs/type_dict.md

@@ -16,6 +16,8 @@ to handle optional keys gracefully.
 
 ## Union operator
 
+**This operator is deprecated.** Use [unpack](#union) instead.
+
 The `|` operator returns the union of two dictionaries. When a key occurs on
 both sides, the value is taken from the right side.
 

examples/tags.rcl

@@ -48,6 +48,6 @@ let var = {
       for tag in tags:
       tag
     };
-    host: group_tags | device_tags
+    host: { ..group_tags, ..device_tags }
   },
 }