As a Nollan, I want a guide of how to create a gamma account on the website, so that I can find out how to create one

### 📝 Description

Currently there exists a guide of how to create a gamma account, but it is located on wikIT, which you need a gamma account to access.

By having a guide on chalmers.it, which could be linked to under applicant/sökande, Nollan could easily find out how to create a gamma account. (Something that many of them struggle with)

Also, as Nollan gets their cid the first day of the reception, there would not have to be any worries that Nollan could get access to gamma "to early".

### ✅ Acceptance Criteria

- [ ] There exists a page on chalmers.it with a step by step guide of how to create a gamma account
- [ ] The page is linked to in applicant/sökande in the header

### 💡 Additional context

_No response_