docs: Add 1.2.0 upgrade guide for Product Module (#4981)

* docs: Add 1.2.0 upgrade guide for Product Module

* Update docs/content/upgrade-guides/modules/product/1-2-0.md

Co-authored-by: Shahed Nasser <shahednasser@gmail.com>

* Update docs/content/upgrade-guides/modules/product/1-2-0.md

Co-authored-by: Shahed Nasser <shahednasser@gmail.com>

* Address pr comments

* address pr comments

* fix lint issue

---------

Co-authored-by: Shahed Nasser <shahednasser@gmail.com>

www/docs/content/upgrade-guides/modules/_category_.json

@@ -0,0 +1,5 @@
+{
+  "position": 4,
+  "link": null,
+  "label": "Modules"
+}

www/docs/content/upgrade-guides/modules/product/1-2-0.md

@@ -0,0 +1,51 @@
+---
+description: 'Actions Required for v.1.2.0'
+sidebar_custom_props:
+  iconName: 'server-stack-solid'
+---
+
+# v1.2.0
+
+Version 1.2.0 of the Product Module introduces minor breaking changes to the `ProductService`.
+
+## Overview
+
+This release contains breaking change to the methods `list` and `listAndCount` in the `ProductService` of the Product Module.
+
+Specifically, the category filter that the service methods accept has changed from `category_ids` to `category_id`.
+
+---
+
+## How to Update
+
+Run the following command in your project:
+
+```bash npm2yarn
+npm install @medusajs/product@1.2.0
+```
+
+---
+
+## Actions Required
+
+### Change usage of Product Module
+
+If you've applied the category filter to the `list` or `listAndCount` methods of the Product Module, you will need to change it as follows:
+
+```ts
+// Before
+ProductService.list({ 
+  category_ids: ["pcat_123", "pcat_456"], 
+})
+ProductService.listAndCount({ 
+  category_ids: ["pcat_123", "pcat_456"], 
+})
+
+// Now
+ProductService.list({ 
+  category_id: ["pcat_123", "pcat_456"], 
+})
+ProductService.listAndCount({ 
+  category_id: ["pcat_123", "pcat_456"], 
+})
+```

www/docs/content/upgrade-guides/modules/product/_category_.json

@@ -0,0 +1,6 @@
+{
+  "label": "Product Module",
+  "customProps": {
+    "reverse": true
+  },
+}

www/docs/sidebars.js

@@ -1866,6 +1866,20 @@ module.exports = {
         },
       ],
     },
+    {
+      type: "category",
+      label: "Modules",
+      collapsible: false,
+      customProps: {
+        sidebar_is_group_headline: true,
+      },
+      items: [
+        {
+          type: "autogenerated",
+          dirName: "upgrade-guides/modules",
+        },
+      ],
+    },
     {
       type: "category",
       label: "Plugins",