Update comment about min Go version (#1023)

This wasn't updated in either #969 or #1017 and is the first thing people read on pkg.go.dev.

Author: JRaspass

chi.go

@@ -1,6 +1,6 @@
 // Package chi is a small, idiomatic and composable router for building HTTP services.
 //
-// chi requires Go 1.14 or newer.
+// chi supports the four most recent major versions of Go.
 //
 // Example:
 //