Point jdk.java.net instead of OracleJDK page. (apache#42)

README.md

@@ -42,7 +42,7 @@ comprehensive documentation, visit:
 ### Step 0) Set up your development environment (OpenJDK 11 or greater)
 
 We'll assume that you know how to get and set up the JDK - if you
-don't, then we suggest starting at https://www.oracle.com/java/ and learning
+don't, then we suggest starting at https://jdk.java.net/ and learning
 more about Java, before returning to this README. Lucene runs with
 Java 11 or later.