DevDocs corrections part 1

Started reviewing the developer docs, finding lots of things to correct. I'll do more later, but please review this batch first so I know what, if anything, needs to be fixed moving forward - I'm not entirely sure on the markdownish format used.
Whoops.  I misread the patch.  I'm also in favor of decapitalizing all instances of Merkle as it has entered generic use.  Please ignore my previous line node.