Added episode endpoint documentation

[DmnChzl]

This is the /episode endpoint documentation 📚, following the issue #45

[lelouchB]

Hey @mrdoomy
This looks great. Just a few little things.

Can you change this line

There are curently `23` episodes sorted by id, more are added every season. 

To something like this.

Currently there are 23 episodes spanning over two seasons released in 2018 and 2019. 
Season 1 premiered on TBS and consists of 10 episodes which are named as **Chapter 1**, **Chapter 2**, etc.

Season 2 premiered in 2019 on Adult Swim and consists of 13 episodes. 

Season 3 is currently in development and it's data will be added after it's release.

[DmnChzl]

Hello again @lelouchB 👋
You're right! It's better now 🙂

[lelouchB]

Great 💯

This issue is done, I will merge this as soon as #41 finishes and the episode endpoint becomes live.

Thanks for your work on this.