At first appears to be typo of idiot, which usually is the case.
But when placed at the end of the sentence(after dot for best effect), it turns combined statement and insult due to being "I do it" squeezed together.
An Idiot who can't spell Idiot correctly
Person 1: You're such an Idoit
Person 2: Man STFU You can't even spell the word Idiot you empty-headed retard
An Idiot who can't even spell Idiot correctly
Person 1: You are an idoit haha LOL!!!
Person 2: Stfu you can't even spell idiot you empty-headed retard.
Someone awesome! The opposite of idiot.
You idoit, what's wrong with you?
Someone who is trying to call someone an Idiot but is is too much of an Idiot to spell it right
"You are an idoit!" The 7 year old says