Displays error message when the spelling is wrong

[KeerthanBhat]

trafficstars

Used a simple try except for handling the TypeError when the word entered in lexico add word has a wrong spelling.

[kshitij10496]

Instead of calling exit, we should return either an empty list or None from this function. (Compare which will be suitable here) The CLI application should catch it and perform the exit.

[KeerthanBhat]

Is this commit fine or anything else that I have to do?