doc: clarify that we don't maintain external doc resources

PR-URL: libuv#284
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

README.md

@@ -72,19 +72,23 @@ NOTE: Windows users need to use make.bat instead of plain 'make'.
 
 Documentation can be browsed online [here](http://docs.libuv.org).
 
+The [tests and benchmarks](https://github.com/libuv/libuv/tree/master/test)
+also serve as API specification and usage examples.
+
 ### Other resources
 
  * [An Introduction to libuv](http://nikhilm.github.com/uvbook/)
    — An overview of libuv with tutorials.
  * [LXJS 2012 talk](http://www.youtube.com/watch?v=nGn60vDSxQ4)
    — High-level introductory talk about libuv.
- * [Tests and benchmarks](https://github.com/libuv/libuv/tree/master/test)
-   — API specification and usage examples.
  * [libuv-dox](https://github.com/thlorenz/libuv-dox)
    — Documenting types and methods of libuv, mostly by reading uv.h.
  * [learnuv](https://github.com/thlorenz/learnuv)
    — Learn uv for fun and profit, a self guided workshop to libuv.
 
+These resources are not handled by libuv maintainers and might be out of
+date. Please verify it before opening new issues.
+
 ## Build Instructions
 
 For GCC there are two build methods: via autotools or via [GYP][].