message: Update docs for Position
  Summary: Add these missing docstrings
diff: @@ -324,11 +324,9 @@ impl DocString {
  /// Line / column for where in a file a symbol is.
  #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
  pub struct Pos {
  - /// Line number.
  - // TODO(nga): explain is it 0-based or 1-based?
  + /// Line number, zero based.
  pub line: usize,
  - /// Column number.
  - // TODO(nga): explain is it 0-based or 1-based?
  + /// Column number, zero based.
  pub column: usize,
  }
  