Adds releae notes

Author: Ecarrion

RELEASE-NOTES.txt

@@ -4,6 +4,7 @@
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 - [**] Products: Now you can duplicate products from the More menu of the product detail screen. [https://github.com/woocommerce/woocommerce-ios/pull/7727]
 - [*] Help center: Added help center web page with FAQs for "Wrong WordPress.com account error" screen. [https://github.com/woocommerce/woocommerce-ios/pull/7747]
+- [*] Widgets: The Today's Stat Widget adds support for bigger fonts. [https://github.com/woocommerce/woocommerce-ios/pull/7752]
 
 10.4
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