writeToBufferState method
Writes a single character and current style attributes at the cursor.
Implementation
void writeToBufferState(String char) {
bufferState[currentLine][currentColumn].character = char;
bufferState[currentLine][currentColumn].foregroundColor = _foregroundColor;
bufferState[currentLine][currentColumn].backgroundColor = _backgroundColor;
bufferState[currentLine][currentColumn].fontStyles = {..._fontStyles};
}