A little hard to tell if a button is disabled for mobile #61

[Aspireve]

Description

The main issue was the user not being able to understand if the button was disabled or not, so to overcome it I changed the text inside the button and made it a bit more informative and once the task gets completed it changes the text within it to indicate that the user can now proceed with the game

The changes I made were

• changed the text in the button space to make it a bit more informative
• included a new statement in the Enable_Continue_Button function that changes the text in the button using the .innerHTML property
• whenever a task is completed it calls onto the Enable_Continue_Button function to change the text

Closes #61

[devkennyy]

Thanks so much, works just as you said.