Syntax lookup: Deprecated decorator

Author: kevanstannard

misc_docs/syntax/decorator_deprecated.mdx

@@ -0,0 +1,38 @@
+---
+id: "deprecated-decorator"
+keywords: ["deprecated", "decorator"]
+name: "@deprecated"
+summary: "This is the `@deprecated` decorator."
+category: "decorators"
+---
+
+The `@deprecated` decorator is used to annotate deprecated types and values. This may be used by ReScript tooling to highlight deprecated code during development.
+
+### Example
+
+<CodeTab labels={["ReScript", "JS Output"]}>
+
+```res
+@deprecated
+type person = {id: int, name: string}
+
+@deprecated
+let customDouble = foo => foo * 2
+
+@deprecated("Use SomeOther.customTriple instead")
+let customTriple = foo => foo * 3
+```
+
+```js
+function customDouble(foo) {
+  return foo << 1;
+}
+
+function customTriple(foo) {
+  return Math.imul(foo, 3);
+}
+```
+
+</CodeTab>
+
+