magento/adobe-stock-integration#1832: Rename renditions stores config fieldset and add comments - modified config fieldset and added comments

Author: joweecaquicla

app/code/Magento/MediaGalleryRenditions/etc/adminhtml/system.xml

@@ -9,7 +9,9 @@
     <system>
         <section id="system">
             <group id="media_gallery_renditions" translate="label" type="text" sortOrder="1010" showInDefault="1" showInWebsite="0" showInStore="0">
-                <label>Media Gallery Renditions</label>
+                <label>Media Gallery Image Size</label>
+                <comment>Resize images to improve performance and decrease the file size. When you use an image from Media Gallery on the storefront, the smaller image is generated and placed instead of the original.
+                    Changing these settings will update all generated images.</comment>
                 <field id="width" translate="label" type="text" sortOrder="10" showInDefault="1" showInWebsite="0" showInStore="0">
                     <label>Max Width</label>
                     <validate>validate-zero-or-greater validate-digits</validate>