Add warnings about lack of maintenance.

README.md

@@ -17,6 +17,11 @@ See the [crate documentation] for details on how to use it.
 
 [crate documentation]: https://docs.rs/dhat
 
+**Warning: this crate is experimental and doesn't work in some configurations.
+Its maintenance is not a high priority of the author. Support requests such as
+issues and pull requests may receive slow responses, or no response at all.
+Sorry!**
+
 ## License
 
 Licensed under either of

src/lib.rs

@@ -21,6 +21,11 @@
 //! then check that they allocated as much heap memory as you expected. This
 //! can be useful for performance-sensitive code.
 //!
+//! **Warning: this crate is experimental and doesn't work in some
+//! configurations. Its maintenance is not a high priority of the author.
+//! Support requests such as issues and pull requests may receive slow
+//! responses, or no response at all. Sorry!**
+//!
 //! # Motivation
 //!
 //! DHAT is a powerful heap profiler that comes with Valgrind. This crate is a