Reword PR 162

Author: dtolnay

README.md

@@ -75,11 +75,10 @@ anyhow = "1.0"
   }
   ```
 
-- If using the stable channel with enabled "backtrace" feature or the nightly
-  channel, a backtrace is captured and printed with the error if the underlying
-  error type does not already provide its own. In order to see backtraces, they
-  must be enabled through the environment variables described in
-  [`std::backtrace`]:
+- If using the nightly channel, or stable with `features = ["backtrace"]`, a
+  a backtrace is captured and printed with the error if the underlying error
+  type does not already provide its own. In order to see backtraces, they must
+  be enabled through the environment variables described in [`std::backtrace`]:
 
   - If you want panics and errors to both have backtraces, set
     `RUST_BACKTRACE=1`;