message: Fix a minor formatting issue.
diff: @@ -1246,7 +1246,7 @@ func @count(%x: i64) -> (i64, i64)
  }
  ```
  -#### Blocks
  +## Blocks
  Syntax:
  @@ -1305,7 +1305,7 @@ of SSA is immediately apparent, and function arguments are no longer a special
  case: they become arguments to the entry block
  [[more rationale](Rationale.md#block-arguments-vs-phi-nodes)].
  -### Operations
  +## Operations
  Syntax:
  @@ -1368,7 +1368,7 @@ reason about IR dumps and manipulate operations in C++, the MLIR compiler
  infrastructure uses C++ templates to make working with them convenient and safe.
  The details of this are not described in this document.
  -## Standard Operations
  +### Standard Operations
  TODO: shape, which returns a 1D tensor, and can take an unknown rank tensor as
  input.
  