Update CONTRIBUTING.md

Updated the CONTRIBUTING.md, based on GitHub requests; moved the information on how to build below enhancing documentation, and added how to view it.

CONTRIBUTING.md

@@ -29,10 +29,6 @@ If VTR does not support your use case, consider [filling an enhancement](#fillin
 Great! Submitting bug-fixes and features is a great way to improve VTR.
 See the guidlines for [submitting code](#submitting-code-to-vtr).
 
-### How do I build the documentation?
-The documentation can be built by using the command `make html` in the `$VTR_ROOT/doc` directory. More information on building
-the document can be found on the [README on the GitHub](https://github.com/verilog-to-routing/vtr-verilog-to-routing/tree/master/doc).
-
 ## The Details
 
 ### Enhancing Documentation
@@ -45,6 +41,9 @@ If you are considering larger changes its best to discuss them first (e.g. file
 
 Once you've made your enhancements [open a pull request](#making-pull-requests) to get your changes considered for inclusion in the documentation.
 
+### How do I build the documentation?
+The documentation can be built by using the command `make html` in the `$VTR_ROOT/doc` directory and you can view it in a web browser by loading the file at $VTR_ROOT/_build/html/index.html. More information on building
+the documentation can be found on the [README on GitHub](https://github.com/verilog-to-routing/vtr-verilog-to-routing/tree/master/doc).
 
 ### Filling Bug Reports
 First, search for [existing issues](https://github.com/verilog-to-routing/vtr-verilog-to-routing/issues?&=) to see if the bug has already been reported.