docs: Fix OpenAlex recipe typo

Author: MoenMi

src/python/openalex.ipynb

@@ -66,7 +66,7 @@
     "\n",
     "An API key is required to access the OpenAlex API. Please see the <a href=\"https://developers.openalex.org/guides/authentication\" target=\"_blank\">Authentication & Pricing page</a> for instructions on how to obtain one.\n",
     "\n",
-    "We keep our email in a `.env` file and use the `dotenv` library to access it. If you would like to use this method, create a `.env` file and add the following line to it:\n",
+    "We keep our API key in a `.env` file and use the `dotenv` library to access it. If you would like to use this method, create a `.env` file and add the following line to it:\n",
     "\n",
     "```text\n",
     "OPENALEX_API_KEY=\"YOUR-API-KEY-HERE\"\n",