Change of README file format to Markdown

Signed-off-by: Alban VIDAL <alban.vidal@zordhak.fr>
2 jobs for social_contract_readme_markdown in 1 minute and 37 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Deploy
passed #131061
pages

00:01:37

passed pages:deploy

00:00:03