Remove old issues

README.md

@@ -135,11 +135,11 @@ How to contribute
 -----------------
 
 The best way to contribute is to try the new build system, report the issues
-you found, and attempt to fix them. Please note the codebase is very unstable
-at present and we expect a lot of further refactoring. The documentation is
-currently non-existent, but we are working on it: [#55][comments-issue],
-[#56][doc-issue]. See also [#239](https://github.com/snowleopard/hadrian/issues/239)
-for a list of issues on the critical path.
+you found, and attempt to fix them. Please note: the codebase is very unstable
+at present and we expect a lot of further refactoring. If you would like to
+work on a particular issue, please let everyone know by adding a comment about
+this. The issues that are currently on the critical path are listed in
+[#239](https://github.com/snowleopard/hadrian/issues/239).
 
 Acknowledgements
 ----------------
@@ -169,6 +169,4 @@ helped me endure and enjoy the project.
 [cross-compilation-issue]: https://github.com/snowleopard/hadrian/issues/177
 [install-issue]: https://github.com/snowleopard/hadrian/issues/219
 [milestones]: https://github.com/snowleopard/hadrian/milestones
-[comments-issue]: https://github.com/snowleopard/hadrian/issues/55
-[doc-issue]: https://github.com/snowleopard/hadrian/issues/56
 [contributors]: https://github.com/snowleopard/hadrian/graphs/contributors