Docs updates (#599)

- Updated docs GH workflow to build and publish javadoc alongside of
docs directory. This would make the docs available at
https://langchain4j.github.io/langchain4j and javadoc at
https://langchain4j.github.io/langchain4j/apidocs/index.html
- Updated javadoc build command in docs GH workflow to do a full project
build (that includes all modules and no exclusions).
- Updated javadoc build in docs GH workflow to run with Java 21 version.

This is in reference to
https://github.com/langchain4j/langchain4j/discussions/596

---------

Co-authored-by: Lize Raes <49833622+LizeRaes@users.noreply.github.com>

.github/workflows/docs.yaml

@@ -23,12 +23,25 @@ jobs:
       url: ${{ steps.deployment.outputs.page_url }}
     steps:
       - uses: actions/checkout@v4
-      - name: Use Node.js
+
+      - name: Set up JDK 21
+        uses: actions/setup-java@v3
+        with:
+          java-version: '21'
+          distribution: 'temurin'
+          cache: 'maven'
+
+      - name: Generate Javadoc
+        run: mvn javadoc:aggregate -DskipTests
+
+      - name: Set up Node.js
         uses: actions/setup-node@v3
         with:
           node-version: '20.x'
+
       - run: cd docs && npm ci
       - run: cd docs && npm run build
+      - run: cp -R target/site/apidocs docs/build/
 
       - name: Setup Pages
         uses: actions/configure-pages@v3

docs/build.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+
+npm ci
+
+npm run build

docs/docusaurus.config.js

@@ -86,7 +86,11 @@ const config = {
                     },
                     {to: '/docs/tutorials', label: 'Tutorials', position: 'left'},
                     {to: '/docs/category/integrations', label: 'Integrations', position: 'left'},
-                    {to: 'https://lizeraes.github.io/langchain4j/apidocs/', label: 'Javadoc', position: 'left'},
+                    {
+                        href: 'https://langchain4j.github.io/langchain4j/apidocs/index.html',
+                        label: 'Javadoc',
+                        position: 'left'
+                    },
                     {to: '/blog', label: 'Blog', position: 'left'},
                     {
                         href: 'https://github.com/langchain4j/langchain4j',

docs/start.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+
+npm ci
+
+npm run start