Spelling fixes (#79)

content/docs.da.md

content/docs.de.md

content/docs.en.md

content/docs.es.md

content/docs.fr.md

content/docs.no.md

content/docs.sv.md

content/docs.zh.md

content/screens.da.md

content/screens.de.md

content/screens.en.md

content/screens.eo.md

content/screens.es.md

content/screens.fr.md

content/screens.no.md

content/screens.sv.md

content/screens.zh.md