updated links to point to jdk rather than jre

added link to comprehensive guide for setting up java

How To.md

 ## Installation
 ### Install Java
-#### Download link
-https://www.java.com/en/download/
+
+#### [Installing java guide](https://gitlab.stud.idi.ntnu.no/it1901/course-material/blob/master/howto/get-java.md "Installing Java")
+
+
+#### Download links
+
+http://jdk.java.net
+https://www.oracle.com/technetwork/java/javase/downloads/index.html
+
 
 #### How and why to uninstall older versions of Java
 https://www.java.com/en/download/faq/remove_olderversions.xml
@@ -10,7 +17,7 @@ https://www.java.com/en/download/faq/remove_olderversions.xml
 #### Download link
 https://git-scm.com/book/en/v2/Getting-Started-Installing-Git
 
-#### For Windows we reccomend Git for Windows
+#### For Windows we recommend Git for Windows
 https://gitforwindows.org/
 
 ### Install Eclipse or Intellij