Data/fix typos in wotc srd sections (#288)

* fixed typos in WOTC SRD sections markdown

* added missing Combat sections to json data

* fixed typos in Sage Advice asides

* fixed typos in wotc srd classes json

* moved asides in classes markdown to more appropriate spots

* fixed typos in subtype-name fields of wotc srd classes

Author: calumbell