Refactor contributions guide for improved readability

doc/contributions-guide.md

@@ -10,11 +10,11 @@ operators, an increasing number of vendors and open source projects have
 augmented the models with additional fields that have not fallen into the
 initial "minimum operationally viable" approach that OpenConfig has taken.
 However, this is not to say that these features are not used, or are not of
-interest for including in the models. It is desirable that these augmentations
-- where they meet the style, and support requirements for including in the
-models - be included within the standard set of models, rather than have many
-different augmentations covering the same feature set. To this end, this
-document outlines a process for external contributions to OpenConfig.
+interest for including in the models. It is desirable that these 
+augmentations - where they meet the style, and support requirements for
+including in the models - be included within the standard set of models,
+rather than have many different augmentations covering the same feature set. 
+To this end, this document outlines a process for external contributions to OpenConfig.
 
 OpenConfig considers schema consistency paramount -- since it greatly impacts
 the usability of the models for consumers be they machine or human. As external