Add deprecation note to README (#129)

README.md

@@ -1,10 +1,12 @@
 # good-fences
 
-> "Good fences make good neighbors."
-— Robert Frost, [*Mending Wall*](https://www.poetryfoundation.org/poems/44266/mending-wall)
+⚠ The JavaScript version of `good-fences` is no longer maintained.  Please see [`good-fences-rs`](https://github.com/Adjective-Object/good-fences-rs-core).
 
 ## What is good-fences?
 
+> "Good fences make good neighbors."
+— Robert Frost, [*Mending Wall*](https://www.poetryfoundation.org/poems/44266/mending-wall)
+
 Good-fences is a tool that allows you to segment a TypeScript project into conceptual areas and manage dependencies between those areas.
 
 This is mostly a concern for large projects with many people working on them, where it is impossible for every developer to have a wholistic understanding of the entire codebase.