docs: rewrite all XML documentation in English per Microsoft guidelines - #461

Non-nullable field 'tt' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Converting null literal or possible null value to non-nullable type.

Converting null literal or possible null value to non-nullable type.

Converting null literal or possible null value to non-nullable type.

Non-nullable field 'baseStream' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'ftab' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'szptr' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'zptr' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field 'quadrant' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.