whitespace validation for input text

[uttej-vsk]

Currently the app allows for empty spaces in the input text area.

There is no validation to prevent users from entering only whitespaces.

We can allow users to enter text if it is not a white space.

@whoiskatrin - I have opened a pull request for this and my bad, I should’ve opened issue before working on it.

I will mention this issue in the PR #52