Update company name (CS Systemes d'Information => CS Group)

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_includes/footer_rugged.html

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_posts/2018-01-24-open-governance-for-rugged.md

_posts/2019-01-04-yannick-is-now-pmc-member.md

_posts/2019-03-05-sebastien-is-now-pmc-member.md

atom.xml

index.html

rugged/atom.xml

rugged/index.html

rugged/overview.html

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stavor/atom.xml

stavor/index.html

stavor/support.html

support.html