Format the elements in the page header

[auge8472]

Add general rules for all direct childs of the page header (body > header), font size rule for h1 and bold font weight for the optional p.

Additionally I added a commit go provide a bigger left and right padding for the direct childs of body on viewport widths of 40em or larger.

[andythenorth]

Hi Auge, I don't want you to miss this :) https://github.com/orgs/OpenTTD/teams/website-people/discussions/1/comments/2

[auge8472]

Hi Auge, I don't want you to miss this :)

I read it before starting this request. The question for me is now: Do you plan to restore the old status?

[andythenorth]

My intent is to get the old theme applied to new frontend as soon as possible, using https://github.com/andythenorth/bananas-frontend-web

After that - unknown. I want to work on newgrfs with my time, not bananas :) I don't know what other people want to see happen.

[auge8472]

In the light of the latest changes I close the PR.