Gpt improvement

[kylexrich]

Changes

• https://github.com/kylexrich/coursegpt/issues/109
• https://github.com/kylexrich/coursegpt/issues/117
• https://github.com/kylexrich/coursegpt/issues/114
• https://github.com/kylexrich/coursegpt/issues/105
• https://github.com/kylexrich/coursegpt/issues/100

Tested on most questions in here, in addition to some assignment related ones, and everything was good!

[kylexrich]

cleaned up some of the code. looks good

Thank you!