docs: clean up markdown

docs/contributing_to_breakpad.md

 # Introduction
 
 Thanks for thinking of contributing to Breakpad! Unfortunately there are some
 pesky legal issues to get out of the way, but they're quick and painless.
 
 ## Legal
 
 If you're doing work individually, not as part of any employment, you'll need to
-sign the <a
-href='http://code.google.com/legal/individual-cla-v1.0.html'>Individual
-Contributor License Agreement</a>. This agreement can be completed
-electronically.
+sign the
+[Individual Contributor License Agreement](https://cla.developers.google.com/clas/new?domain=DOMAIN_GOOGLE&kind=KIND_INDIVIDUAL).
+This agreement can be completed electronically.
 
 If you're contributing to Breakpad as part of your employment with another
-organization, you'll need to sign a <a
-href='http://code.google.com/legal/corporate-cla-v1.0.html'> Corporate
-Contributor License Agreement</a>. Once completed this document will need to be
-faxed.
+organization, you'll need to sign a
+[Corporate Contributor License Agreement](https://cla.developers.google.com/clas/new?domain=DOMAIN_GOOGLE&kind=KIND_CORPORATE).
+Once completed this document will need to be faxed.
 
 **_IMPORTANT_**: The authors(you!) of the contributions will maintain all
 copyrights; the agreements you sign will grant rights to Google to use your
 work.
 
 Thanks, and if you have any questions let me know and I'll loop in the legal guy
 here to get you an answer.
 
 ## Technical
 
 Once you have signed the agreement you can be added to our contributors list and
 have write access to code. For full details on getting started see our trunk
-`README`.
+[README](/README.md).
 
 ## List of people who have signed contributor agreements
 
 None so far.