message: docs: update links in contrib guide
diff: @@ -16,11 +16,9 @@ Please fill out either the individual or corporate Contributor License Agreement
  (CLA).
  * If you are an individual writing original source code and you're sure you
  - own the intellectual property, then you'll need to sign an [individual CLA]
  - (https://developers.google.com/open-source/cla/individual).
  + own the intellectual property, then you'll need to sign an [individual CLA](https://developers.google.com/open-source/cla/individual).
  * If you work for a company that wants to allow you to contribute your work,
  - then you'll need to sign a [corporate CLA]
  - (https://developers.google.com/open-source/cla/corporate).
  + then you'll need to sign a [corporate CLA](https://developers.google.com/open-source/cla/corporate).
  Follow either of the two links above to access the appropriate CLA and
  instructions for how to sign and return it. Once we receive it, we'll be able to
  