message: docs(error-warnings-details): fix header for E021
diff: @@ -218,7 +218,7 @@ class ErrorClass {
  }
  ```
  -## PropOptions.ref dosnt support Arrays [E021]
  +### PropOptions.ref dosnt support Arrays [E021]
  Error: `"PropOptions.ref" dosnt support Arrays (got "${gotType.dim}" dimensions at "${name}.${key}") [E021]`
  