Add link to ISLE language reference to ISLE Cranelift integration doc.

cranelift/docs/isle-integration.md

@@ -9,7 +9,8 @@ ISLE is a domain-specific language for authoring instruction selection and
 rewrite rules. ISLE source text is [compiled down into Rust
 code](https://github.com/bytecodealliance/wasmtime/tree/main/cranelift/isle#implementation).
 
-TODO: link to @cfallin's language reference/tutorial
+Documentation on the ISLE language itself can be found
+[here](../isle/docs/language-reference.md).
 
 ## How does ISLE integrate with the build system?
 

cranelift/isle/docs/language-reference.md

@@ -8,6 +8,9 @@ backend more naturally. ISLE was first [described in RFC
 by and lives in the Cranelift tree in
 [cranelift/isle](https://github.com/bytecodealliance/wasmtime/tree/main/cranelift/isle).
 
+Documentation on how ISLE is used in Cranelift can be found
+[here](../../docs/isle-integration.md).
+
 ## Intro and Whirlwind Tour: DSL for Instruction Lowering
 
 The goal of ISLE is to represent *instruction lowering patterns*. An