Add accumulated cost calculator

[felixbade]

Using OpenAI tokenizer? Or if it’s complicated, just number of words.

[felixbade]

This is distracting if it's visible all the time. Needs to be on the settings page.

[felixbade]

Add a link to https://platform.openai.com/account/usage

• More trust-worthy
• Easier to understand where the money goes
• Accounts for the free trial
• Accounts for pricing changes

[felixbade]

”Your usage” as the first item in the footer:

[felixbade]

Fixed in 7c6bdb2