Minor formatting spelling corrections

I decided to read through the entire documentation base to familiarize myself, and figured whilst I was at it I could correct any minor spelling mistakes or formatting issues I found. I've confirmed all the formatting works "as intended" by running Hugo locally and viewing the rendered site, but I guess if the version of Hugo is different it could differ?

Happy to have any changes rejected or challenged, though I've tried not to change any actual content, only spelling or formatting, so hopefully nothing will be controversial. 😄