LuaDocs/Desc attributes spelling fixes

I have gone through the Desc attributes used during the LuaDocs generation and made some spelling, punctuation, and consistency fixes. If desired I would not mind going through the other Desc attributes as well.
I removed the single quotation marks here to be consistent with all the other strings I saw, I am not sure if this is desired or that changing the variable names in the other strings to be quoted is preferred. The markdown would probably be more readable if these variable names were marked as code, but this would "pollute" the Description attributes with markdown formatting.