Include credits

shards_of_power.rb

@@ -144,6 +144,12 @@ class ShardsOfPower
 
 		pdf.text "There are multiple chapters in this book. Each of them covers a specific set of topics.\n\n<b>Chapter One</b> is ithe Introduction. It is what you are reading now. It gives the mission statement, the credits, and a few other key details before you get into the spells and the Conditions.\n\n<b>Chapter Two</b> is the megagrimoire. It is a grimoire of grimoires, much like the book that White Wolf released when they still called themselves that, and is a combined set of spells that the players of this community have mutually agreed are at least somewhat reasonable. Many of us helped each other write these spells. All of their names will be listed in them, alphabetically.", :inline_format => true
 
+		start_section "Credits"
+
+		spell_authors = spells.collect { |spell| spell.authors }.flatten.uniq.sort
+
+		pdf.text "The following users have contributed to Shards of Power, in alphabetical order: #{spell_authors.to_list}"
+
 		start_chapter("Two", "Spells")
 
 		spells.group_by(&:primary_arcanum).sort_by { |arcanum, spells| arcanum }.to_h.each do |arcanum, arcanum_spells|