fix: docs fix a broken Internal URL to Open Prices (#10852)

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### What
Internal URL fixed
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docs/reference/api-tutorials/product-prices.md

@@ -4,5 +4,5 @@
 * We ask contributors to provide a proof of the price, in the form of a photo of the price tag or receipt. This is to make it easier to ensure data quality.
 
 ### Links
-* Please read the FAQ at [https://prices.openfoodfacts.org/]([https://prices.openfoodfacts.org/)
+* Please read the FAQ at [https://prices.openfoodfacts.org/](https://prices.openfoodfacts.org/)
 * The API is located at [https://prices.openfoodfacts.org/api/docs](https://prices.openfoodfacts.org/api/docs)