Document Wiley TDM fulltext fetcher setup (#622)

* Document Wiley TDM fulltext fetcher setup

* Exclude onlinelibrary.wiley.com from link inspector

Author: hagerm98

.linkspector.yml

@@ -3,3 +3,5 @@ dirs:
 useGitIgnore: true
 ignorePatterns:
   - pattern: '^https://arxiv\.org/'
+  # Automated access blocked by Cloudflare, see issue for context: https://github.com/JabRef/jabref/issues/13404
+  - pattern: "onlinelibrary\\.wiley\\.com"

en/.gitbook/assets/preferences-web-search-api-keys.png

@@ -15,3 +15,40 @@ Then, JabRef uses online services to find a PDF. (Implementation details are pro
 Result of the look up:
 
 <figure><img src="../.gitbook/assets/look-up-result.png" alt=""><figcaption><p>Look up result</p></figcaption></figure>
+
+## Supported sources
+
+JabRef uses different publishers and services to find full text documents. When multiple sources find a PDF for the same entry, JabRef prefers results from higher-trust sources (e.g., a publisher's own site is preferred over a meta-search aggregator).
+
+## Configuring API keys
+
+Some publishers/services require an API key to work. You can configure API keys in **File > Preferences > Web search**.
+
+<figure><img src="../.gitbook/assets/preferences-web-search-api-keys.png" alt=""><figcaption><p>Configuring API keys in Preferences > Web search</p></figcaption></figure>
+
+For each publisher that supports an API key, click the **"Configure API key"** button next to it to enter your key.
+
+The following publishers require API keys:
+
+| Publisher | API key |
+| --- | --- |
+| Wiley TDM | **Required.** Without a token, Wiley PDF downloads will fail (Wiley blocks direct downloads). See [Wiley setup](#wiley-tdm-setup) below. |
+
+### Wiley TDM setup
+
+Wiley journals cannot be downloaded directly because Wiley blocks automated access with Cloudflare protection. Instead, JabRef uses Wiley's official [Text and Data Mining (TDM) API](https://onlinelibrary.wiley.com/library-info/resources/text-and-datamining) to retrieve PDFs.
+
+To set it up:
+
+1. Go to the [Wiley TDM page](https://onlinelibrary.wiley.com/library-info/resources/text-and-datamining) and sign in with your Wiley account.
+2. Accept the click-through license agreement to receive your personal TDM API token.
+3. In JabRef, go to **File > Preferences > Web search**.
+4. Find **"Wiley TDM"** in the list, click **"Configure API key"**, paste your token, and check **"Save API key to use in future?"**.
+
+<figure><img src="../.gitbook/assets/preferences-wiley-tdm-token.png" alt=""><figcaption><p>Configuring the Wiley TDM token</p></figcaption></figure>
+
+After configuring the token, **Lookup > Find full text documents online** will be able to download PDFs for Wiley DOIs.
+
+{% hint style="info" %}
+The Wiley TDM token is personal and non-transferable. Each user needs to obtain their own token. You can only access articles that your institution subscribes to.
+{% endhint %}