Move legacy release branch readme

Author: interactivellama

legacy-release-branches.md renamed to docs/legacy-release-branches.md

@@ -2,7 +2,7 @@
 
 Breaking changes do not happen often in this library. There are typically 20+ releases between breaking changes. Sometimes a consuming team needs some time to update their application or test suite. 
 
-* When a large or breaking change occurs, a library maintainer will create a branch such as 0.7.x or 0.8.x. Submit your pull request to that branch if you need a fix in a legacy release branch. Then, to get a release, please create a pull request with release notes (see releases.md) to that branch. Historically, breaking changes happen about once or twice a year.
+* When a large or breaking change occurs, a library maintainer will create a branch such as 0.7.x or 0.8.x. Submit your pull request to that branch if you need a fix in a legacy release branch. Then, to get a release, please create a pull request with release notes (see [release.md](release.md)) to that branch. Historically, breaking changes happen about once or twice a year.
 * If you needed a fix in  a legacy release branch, you should pull request into it, and then a maintainer will also merge the fix into master if it applies, too.
 * Pushing fixes from `master` to a legacy release branch is not advised.