Finish every theory section in simulations. [more people can work for this issues]

[mattqdev]

Describe the feature

We need physics teachers or people who can explain it well for writing some theory on the simulation pages (no coding required, just JSON formatting).

src/data/chapters.json

Motivation

Most of theory section is empty.

Alternatives considered

No response

Additional context

No response

[Yukesh-30]

I would like to contribute to this theory section. Could you please assign it to me.

[physicshub]

Hello! Thank you for your help! I'm going to assign you this issue, can you tell which simulation do you want to write the theory about?

[Yukesh-30]

I would like to write theory for Simple Pendulum.