Fix word issue on our-philosophy.md on presta-cms-core
Fix word issue on technologies.md on presta-cms-core
Fix word issue on help-support.md on presta-cms-core
Fix word issue on release-process.md on presta-cms-core
Fix word issue on contributing.md on presta-cms-core
Fix word issue on index.html
Fix word issue on index.md on presta-cms-theme
Fix word issue on index.md on presta-cms-media