content(resources): add content to lang intro pages

src/content/resources/java/intro.md

@@ -5,6 +5,31 @@ created_at: 2019/12/15
 title: Java
 ---
 
-## Java
+## Documentation
 
-The Java resources ^\_-
+- [Java docs](https://docs.oracle.com/en/java/javase/11/)
+
+## Free Books
+
+- [https://goo.gl/WZTC9C](https://goo.gl/WZTC9C)
+
+## Video
+
+- [EJ Media](https://goo.gl/tC1KwC)
+- [Derek Banas](https://goo.gl/9eVFkE)
+- [Free With Registration | Cave of Programming](https://goo.gl/NXTo4H)
+
+## Guides
+
+- [Learn By Examples | Beginnersbook.com](https://goo.gl/3nDWeQ)
+
+## Useful Repositories
+
+- [Frameworks](https://goo.gl/EoLvrH)
+- [Design patterns](https://goo.gl/wT7SfQ)
+
+## Other
+
+- [History of Java](https://en.wikipedia.org/wiki/Java_version_history)
+- [Wikibooks](https://en.wikibooks.org/wiki/Java_Programming/History)
+- [Timeline](https://oracle.com.edgesuite.net/timeline/java/)