rename spacings variables and replace 6px spacing by 8px spacing

assets/sass/_theme/_configuration.sass

assets/sass/_theme/blocks/base.sass

assets/sass/_theme/blocks/call_to_action.sass

assets/sass/_theme/blocks/chapter.sass

assets/sass/_theme/blocks/contact.sass

assets/sass/_theme/blocks/definitions.sass

assets/sass/_theme/blocks/features.sass

assets/sass/_theme/blocks/files.sass

assets/sass/_theme/blocks/image.sass

assets/sass/_theme/blocks/key_figures.sass

assets/sass/_theme/blocks/organizations.sass

assets/sass/_theme/blocks/pages.sass

assets/sass/_theme/blocks/persons.sass

assets/sass/_theme/blocks/posts.sass

assets/sass/_theme/blocks/programs.sass

assets/sass/_theme/blocks/sitemap.sass

assets/sass/_theme/blocks/testimonials.sass

assets/sass/_theme/blocks/timeline.sass

assets/sass/_theme/blocks/video.sass

assets/sass/_theme/dependencies/glightbox.sass