update EMBrACE website

[lenaRB]

@adrpo: Could be useful to update CRML specifications found on https://www.embrace-project.org/ to avoid any misunderstandings.
Latest CRML specifications is version 1.2 and can be found there: language_specification

We could maybe link from the embrace website to https://github.com/lenaRB/crml-compiler/tree/9900992bc26872c7fe07b2b07e9e5a4995076bd6/language_specification
so we don't need to update in the old SVN.

[adrpo]

Should we not point to the new repo?

[lenaRB]

• retire the old page with a message that the project has concluded and CRML resources can now be found somewhere else
• point the page to read from a GitHub pages repo in documentation/embrace-website
• redirect to the GitHub page