Add version number and release notes link to edex install page

- if we don't like this placement we can come up with something else?

docs/install/install-edex.md

@@ -4,6 +4,15 @@ EDEX is the **E**nvironmental **D**ata **Ex**change system that represents the b
 
 ---
 
+## Latest Version
+
+**18.2.1-1**
+
+[**View release notes**](https://www.unidata.ucar.edu/blogs/news/tags/awips-release)
+
+---
+
+
 ## System requirements
 
 - 64-bit CentOS/RHEL 7
@@ -386,4 +395,4 @@ sudo yum remove awips2-*
 **6. Remove everything in the /awips2 directory**
 ```
 rm -rf /awips2/*
-```
+```