Add .gitignore about website

[danielpeintner]

You might be right, let's ignore all files vscode files (see c066f89)

[danielpeintner]

I did have a local .gitignore but forgot to check it in.
In the meanwhile I did so with my local requirements, see d7106e3

Do you need more ignores?

[fatadel]

@danielpeintner I would also add .vscode

[danielpeintner]

Did so, see 58add5e

[fatadel]

Thank you, @danielpeintner!

[fatadel]

I would remove !.vscode/settings.json from .gitignore.
I think there are more cases when we don't want to exchange this file rather than cases when we want.
For example, the spell checker extension I use adds ignored words to that file. I suppose they shouldn't be in the repo.