discuss issue situation in README

fixes scala#62

Author: SethTisue

README.md

@@ -24,6 +24,13 @@ If you are cross-building a project that uses scala-xml with both Scala 2.10 and
 
 This library is community-maintained. The lead maintainers are [@aaron_s_hawley](https://github.com/ashawley) and [@biswanaths](https://github.com/biswanaths).
 
+## Issues
+
+Many old issues from the Scala JIRA issue tracker have been migrated
+here, but not all of them. Community assistance identifying and
+migrating still-relevant issues is welcome.  See [this
+page](https://github.com/scala/scala-xml/issues/62) for details.
+
 ## Security best practices
 
 The XML spec has some features that are best turned off, to avoid unsavory things like file system access, DoS attacks,... Issue [#17](https://github.com/scala/scala-xml/issues/17) tracks the recommended way of configuring the XML parser used by scala-xml to avoid these. This is by no means an exhaustive list. We'll be happy to incorporate your suggestions -- just comment on the ticket!