rfc, cfg-path-version: add error-chain#101 as an example.

Author: Centril

text/0000-cfg-path-version.md

@@ -64,8 +64,11 @@ proposed in the [summary] we aim to make retaining *compatibility* and
 supporting more compiler versions *pain-free* and to give authors a lot
 of *control* over what is supported and what is not.
 
-A minor use case this RFC supports is to work around compiler bugs by
-checking if we are on a particular version.
+[rust-lang-nursery/error-chain#101]: https://github.com/rust-lang-nursery/error-chain/issues/101
+
+Another use case this RFC supports is to work around compiler bugs by
+checking if we are on a particular version. An example where this occurred
+is documented in [rust-lang-nursery/error-chain#101].
 
 # Guide-level explanation
 [guide-level-explanation]: #guide-level-explanation