feat: add random punctuation to generated word lists and update documentation to reflect this behavior

[johnny603]

No description provided.

[David-Else]

I tried this and it adds punctuation to every word, which I don't think is natural:

Maybe every 6 or so words would be better? Ideally it would be an option along with turning this feature on and off.

Thanks!

EDIT, this seems to work:

		// Only add punctuation if:
		// - it's the 6th word in a group (i+1 % 6 == 0)
		// - and NOT the last word overall
		if (i+1)%6 == 0 && i != n-1 {
			punct = punctuations[rand.Int()%len(punctuations)]
		}

[David-Else]

I updated it with #65