Fix scaleGen example and use Authors@R

[courtiol]

This PR solves 2 old issues:

Fixes #255, a small typo in the doc

Fixes #254, a broken example

For #254 the core idea that was there (comparing different scaling methods) cannot be applied because the function scaleGen() does not allow for such a thing. I tried to follow the original spirit as much as possible by comparing scaling in-PCA vs using scaleGen(), but it is not particularly insightful so an alternative would be to cut short the example.

[zkamvar]

Hi @courtiol, would you mind adding yourself to the Authors field in the DESCRIPTION file with a [ctb] tag?

[courtiol]

@zkamvar I took the opportunity to refresh a bit the DESCRIPTION file, so please double check.
I switched the declaration of authorship to the more modern Authors@R syntax.
That implied that I had to fill in the tags which were not present.
I listed all as ctb but you ("cre" + "aut") and @thibautjombart ("aut").
I added your ORCID number but did not bother with the others.
I did try for @thibautjombart but could not make sure of which ORCID number was good as several profile exist and none is public...

[zkamvar]

@zkamvar I took the opportunity to refresh a bit the DESCRIPTION file, so please double check.
I switched the declaration of authorship to the more modern Authors@R syntax.
That implied that I had to fill in the tags which were not present.
I listed all as ctb but you ("cre" + "aut") and @thibautjombart ("aut").
I added your ORCID number but did not bother with the others.
I did try for @thibautjombart but could not make sure of which ORCID number was good as several profile exist and none is public...

Thank you! This was something I had been putting off for a while. The only thing I would request from this is to put @thibautjombart first since he was the first author of the package (I've taken over maintenance recently to expedite bug fixes and features).

Additionally, I've found his ORCiD from https://f1000research.com/articles/8-139/v1: 0000-0003-2226-8692

[courtiol]

This should be OK now!

[zkamvar]

Looks good to me! Thank you for the contribution :)