Fix Added cFE User's Guide Reference to README.md
* Fix Add a reference to cFE User's Guide to cFE README.md
This reference was placed toward the top of the document, before the Version History section.
@@ -6,6 +6,8 @@ This repository contains NASA's Core Flight Executive (cFE), which is a framewor
This is a collection of services and associated framework to be located in the `cfe` subdirectory of a cFS Mission Tree. The Core Flight System is bundled at <https://github.com/nasa/cFS>, which includes build and execution instructions.
+The detailed cFE user's guide can be viewed at <https://github.com/nasa/cFS/blob/gh-pages/cFE_Users_Guide.pdf>.
+
## Version History
### Development Build: 6.7.20
