Capacity check of end-notched beam

Links:

• https://github.com/Anthrazit68/NODEMaple
• https://www.moelven.com/globalassets/moelven-limtre/limtre_eksmpl_digital.pdf
• https://www.moelven.com/globalassets/moelven-limtre/limtreboka_2015_el2.pdf