feature: Disable button for empty comment field (#37)

[arsen1c]

Fixes issue #37 .

This commit disables the comment button if the text field is empty.

Before

After

Now the comment button will only be available when some content is provided in the textarea.

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[harshmangalam]

Great @arsen1c but here need to add three changes

• use solidjs classList to add dynamic class for better optimization
• also trim input value otherwise empty space will again enable the btn
• add spacing between comment field and btn

[arsen1c]

That's a valid point, I will add those.