Minor api.md changes
Minor api.md changes

* fixed json typos
* changed /account/delete to /account/destroy
* fixed error example

jamonation/fxa-auth-server,dannycoates/picl-idp,shane-tomlinson/fxa-auth-server,eoger/fxa-auth-server,jrgm/fxa-auth-server,TDA/fxa-auth-server,jamonation/fxa-auth-server,chilts/fxa-auth-server,chilts/fxa-auth-server,mozilla/fxa-auth-server,chilts/fxa-auth-server,eoger/fxa-auth-server,jamonation/fxa-auth-server,shane-tomlinson/fxa-auth-server,dannycoates/picl-idp,mozilla/fxa-auth-server,shane-tomlinson/fxa-auth-server,mozilla/fxa-auth-server,dannycoates/picl-idp,mozilla/fxa-auth-server,jrgm/fxa-auth-server,eoger/fxa-auth-server,TDA/fxa-auth-server,shane-tomlinson/fxa-auth-server,eoger/fxa-auth-server,TDA/fxa-auth-server,dannycoates/picl-idp,jamonation/fxa-auth-server,chilts/fxa-auth-server,TDA/fxa-auth-server,jrgm/fxa-auth-server,jrgm/fxa-auth-server