chore(docs): update docs on java publishing (#5487)

* update docs on java publishing

* hide table of contents

* update layout

* remove accordion

---------

Co-authored-by: fern-bot <[email protected]>

fern/pages/sdks/integration/maven-central.mdx

@@ -2,9 +2,88 @@
 title: Publish your Java SDK with Maven
 ---
 
-To make your Java SDK publicly accessible, publish to [Maven](https://central.sonatype.com/). Once you've followed the steps below to connect your Maven account to your SDK, Fern will automatically publish the latest version of your SDK.  
+To make your Java SDK publicly accessible, publish to [Maven Central](https://central.sonatype.com/). Once you've followed the steps below to connect your Maven account to your SDK, Fern will automatically publish the latest version of your SDK.  
 
-## Creating a Maven username and password
+<Info>
+For more information on the differences between the Central Portal and OSSRH, see the [Maven Central documentation](https://central.sonatype.org/faq/what-is-different-between-central-portal-and-legacy-ossrh/).
+</Info>
+
+## Publish via the Central Portal (recommended)
+<Steps>
+### Log In (or create account) and navigate to your profile
+Log into [https://central.sonatype.com/account](https://central.sonatype.com/account).
+
+### Click on `Generate User Token`
+
+Click on `Generate User Token`.
+
+<Frame>
+  <img src="maven-user-token.png" alt="Select user token" />
+</Frame>
+
+### Confirm generation
+
+You will be asked to confirm the generation of the token. This will invalidate any existing token. Click on `Ok`.
+
+### Add Maven Central credentials to GitHub Secrets
+
+You'll need to store two repository secrets in your **fern configuration repository** (**i.e. not the Java SDK repository**),
+one for the username and one for the password.
+
+<Frame>
+  <img src="github-secret.png" alt="Adding GitHub Repository Secret" />
+</Frame>
+
+<Info>
+  For each, select **New repository secret**. Name your secret (we recommend `MAVEN_USERNAME` and `MAVEN_PASSWORD`,
+  respectively), add the corresponding value, and click **Add secret**.
+</Info>
+
+### Sign with GPG
+
+If you don't have gpg installed, you can download the binary from [https://gnupg.org/download/index.html](https://gnupg.org/download/index.html), or install it via package manager.
+
+If you already have a GPG key, you can list your keys:
+
+```sh
+gpg --list-secret-keys --keyid-format LONG
+```
+
+If you don't have a GPG key, you can generate a new one:
+
+```sh
+gpg --gen-key
+```
+
+To export your secret key, run:
+
+```sh
+gpg --export-secret-keys --armor KEY_ID
+```
+
+Be sure to replace `KEY_ID` with the key ID of the key you want to export.
+
+More information is available on [Maven Central's GPG validation page](https://central.sonatype.org/publish/requirements/gpg/).
+
+### Add GPG Signature to GitHub Secrets
+
+You'll need to store repository secrets in your **fern configuration repository**,
+for the GPG key id, secret key, and password.
+
+<Frame>
+  <img src="github-secret.png" alt="Adding GitHub Repository Secret" />
+</Frame>
+
+<Info>
+  For each, select **New repository secret**. Name your secret (we recommend `MAVEN_CENTRAL_SECRET_KEY_KEY_ID`, `MAVEN_CENTRAL_SECRET_KEY`, and `MAVEN_CENTRAL_SECRET_KEY_PASSWORD`, respectively), add the corresponding value, and click **Add secret**.
+</Info>
+
+
+</Steps>
+
+Once you regenerate your SDK, a GitHub action will run to publish directly to Maven!
+
+## Publish via OSSRH (legacy)
 
 <Steps>
 ### Log In (or create account)
@@ -51,4 +130,5 @@ one for the username and one for the password.
 
 </Steps>
 
-Once you regenerate your SDK, a GitHub action will run to publish directly to Maven!
+Once you regenerate your SDK, a GitHub action will run to publish directly to Maven!
+