Merge branch 'English_translation' into main

Calculator.java

CalculatorTest.java

README.md

additional_information_about_tests.md

fin/Laskin.java

fin/LaskinTest.java

fin/README_fin.md

fin/asennus.md

fin/eka_testi.md

fin/lisaa_testeja.md

fin/lisatietoa_testeista.md

fin/testien_suoritus.md

fin/viikko4.md

fin_pics/add_test.png

fin_pics/all_tests_done.png

fin_pics/dependency_search.png

fin_pics/reload_button.png

fin_pics/run_all_tests.png

fin_pics/run_test.png

fin_pics/test_done.png