Use github login to identify authors

[prudhomm]

there is now a metadata field in our json files.
I suggest that when we use authors we actually use the github login to identify to authors.
we can then retrieve further information about the authors using a github REST API request

the list of authors can be obtained by looking at the list of people who contributed to github using blame button for example
eg https://github.com/feelpp/toolbox/blame/master/examples/modules/csm/pages/sensor/index.adoc

as an example:

"Metadata":
    {
        "version": "1",
        "author": ["vincentchabannes","prudhomm","lberti","jobinhio"],
        "date": "23/09/2022",
        "references":[""]
}