Add reference to folder

CONTRIBUTING.md

@@ -43,12 +43,14 @@ and let us know if it's not up-to-date (even better, submit a PR with your  corr
 
 ## Design Process
 
-In order to enable efficient collaboration over design documents, the following process must be followed:
+In order to enable efficient collaboration over design documents, the following process should be followed:
 
 1. Open an issue describing the requirements and constraints the design must satisfy
    + Provide a clear list of use-cases that the design intends to address
-2. Open a pull request with a Markdown document describing the proposed design
+2. Open a pull request with a Markdown document describing the proposed design. The document should be placed in the
+   `designs` directory at the root of the repository.
    + Design discussions are tracked using the comment stream of the pull request
+   + The design document will be merged in and retained as if it were code
 
 ## Style Guide