message: Update Ch-2.md
  by Zhang
  Update Ch-2.md
  Closes
diff: @@ -25,7 +25,7 @@ terminology) or types.
  ## MLIR Module, Functions, Blocks, and Operations
  -[Language reference](LangRef.md#operations)
  +[Language reference](../../LangRef.md#operations)
  In MLIR (like in LLVM), the top level structure for the IR is a Module
  (equivalent to a translation unit in C/C++). A module contains a list of
  