Syntax lookup: Add @warning (#676)

Author: fhammerschmidt

misc_docs/syntax/decorator_expression_warning.mdx

@@ -0,0 +1,33 @@
+---
+id: "expression-warning-decorator"
+keywords: ["warning", "decorator"]
+name: "@warning"
+summary: "This is the `@warning` decorator."
+category: "decorators"
+---
+
+The `@warning` decorator is used to modify the enabled compiler warnings for types, values and submodules. See [here](/docs/manual/latest/warning-numbers) for all available warning numbers.
+
+### Examples
+
+<CodeTab labels={["ReScript", "JS Output"]}>
+
+```res
+// Disables warning 27 for the deepClone function
+@warning("-27")
+let deepClone = (obj: 'a): 'a => %raw(`
+  JSON.parse(JSON.stringify(obj))
+`); 
+```
+
+```js
+function deepClone(obj) {
+  return (JSON.parse(JSON.stringify(obj)));
+}
+```
+
+</CodeTab>
+
+### References
+
+* [Warning Numbers](/docs/manual/latest/warning-numbers)

pages/docs/manual/latest/warning-numbers.mdx

@@ -4,12 +4,12 @@ description: "Available compiler warning numbers in ReScript"
 canonical: "/docs/manual/latest/warning-numbers"
 ---
 
-import {make as WarningTable} from "src/components/WarningTable.mjs"
+import { make as WarningTable } from "src/components/WarningTable.mjs";
 
 # Warning Numbers
 
 You can configure which warnings the ReScript compiler generates
 [in the build configuration](/docs/manual/latest/build-configuration#warnings) or
-[using the `@@warning()` decorator](/syntax-lookup#module-warning-decorator).
+using the [`@warning()`](/syntax-lookup#expression-warning-decorator) or the [`@@warning()`](/syntax-lookup#module-warning-decorator) decorator.
 
 <WarningTable />