Fixed documentation of operator[]

Co-authored-by: Silvio Traversaro <[email protected]>

include/matioCpp/Variable.h

@@ -329,7 +329,7 @@ class matioCpp::Variable
  bool isValid() const;
 
  /**
- * @brief Access field at a specific index.
+ * @brief Access field with specific name.
  * @param el The name of the field to be accessed.
  * @return A Variable with a weak ownership to the underlying mat variable. This means that the data can be changed,
  * but the variable cannot be resized and the name cannot change.
@@ -339,7 +339,7 @@ class matioCpp::Variable
  matioCpp::Variable operator[](const std::string& el);
 
  /**
- * @brief Access field at a specific index.
+ * @brief Access field with specific name.
  * @param el The name of the field to be accessed.
  * @warning Each element of el has to be strictly smaller than the corresponding dimension.
  * @return A const Variable with a weak ownership to the underlying mat variable.