Clarify various abbreviations and acronyms

[gizmecano]

Some abbreviations and/or acronyms listed below can be explicitly written for a better understanding:

• [x] API => interface de programmation (API) (9ddf1d40a874ffa5ea7409c70692b7932ce1757d)
• [x] EU => Union européenne (f82bc257d16e1b55a51a0573fc6394960b1336fb)
• [x] FTP => protocole de transfert de fichier (FTP) (ca05f798643825202a3553cb78077d0a8de68221)
• [x] SEO => optimisé pour les moteurs de recherche (SEO) (abd951e25dd33be7ba5dae929dbb7abeca5d3f2e)
• [x] URL => adresse universelle (URL) (bb80c6f24f6bee889acc000fcdff653a5d68fe64)
• [x] US => États-Unis (bac8523c490e5dd3c8f71f293c100b9fe4e79ce1)