Updated sheet.json and pathfinder-neceros.html

Added currency and experience table below the skill table.
Added tooltips for every field that'll show the field's attribute or
ability name.
Added a max calculation box to the feats section so users can add their
own custom max values for and abilities (ie 3 + @{CHA-mod}).

Updated the json instructions to be more descriptive of the sheet. Also
added my roll20userid.