Show markdown description text on item detail page

* Update build process to *not* copy over prerendered pages during a
  regular build (only during a `dist` build)
* Add dependency on npm "markdown" package and include it in the
  scripts loaded in the default layout
* Update the Item model to be able to load from a *.cg file
* Add an ItemParser to process the `item.cg` file
* Update the general parser to be able to work with HereDoc-style
  text blocks
* Add a markdown-specific stylesheet
* Add a sample of the `item.cg` file format (Advanced Crafting Table)

src/coffee/models/parser_versions/command_parser_version_base.coffee

@@ -78,7 +78,7 @@ module.exports = class CommandParserVersionBase
         line = line.trim()
         return [] if line.length is 0
 
-        hereDoc = @_parseHereDoc line
+        [line, hereDoc] = @_parseHereDoc line
 
         lineParts = (part.trim() for part in line.split(';'))
         commands = []
@@ -89,8 +89,10 @@ module.exports = class CommandParserVersionBase
             if not match? then throw new Error "Expected <command>: <args>, but found: \"#{linePart}\""
 
             args = []
-            args = (s.trim() for s in match[2].split(',')) if match[2]?
-            args.push hereDoc if hereDoc
+            args = (s for s in match[2].split(',') when s.length > 0) if match[2]?
+            args = (s.trim() for s in args)
+            args = (s for s in args when s.length > 0)
+            args.push hereDoc if hereDoc?
             commands.push name:match[1], args:args
 
         return commands
@@ -107,9 +109,11 @@ module.exports = class CommandParserVersionBase
 
     _parseHereDoc: (line)->
         hereDocIndex = line.indexOf '<<-'
-        return null unless hereDocIndex isnt -1
+        return [line, null] unless hereDocIndex isnt -1
 
         hereDocStopText = line[hereDocIndex+3...line.length]
+        line = line[0...hereDocIndex]
+
         hereDocLines = []
         while true
             @_lineNumber += 1
@@ -120,11 +124,11 @@ module.exports = class CommandParserVersionBase
             hereDocLines.push nextLine
 
         shortestIndent = Number.MAX_VALUE
-        for line in hereDocLines
-            shortestIndent = Math.min line.match(/( *).*/)[1].length, shortestIndent
+        for hereDocLine in hereDocLines
+            shortestIndent = Math.min hereDocLine.match(/( *).*/)[1].length, shortestIndent
 
         for i in [0...hereDocLines.length]
             hereDocLines[i] = hereDocLines[i][shortestIndent..]
 
-        return null unless hereDocLines.length > 0
-        return hereDocLines.join '\n'
+        return [line, null] unless hereDocLines.length > 0
+        return [line, hereDocLines.join('\n')]

src/coffee/models/parser_versions/item_parser_v1.coffee

@@ -22,16 +22,17 @@ module.exports = class ItemParserV1 extends CommandParserVersionBase
     # Command Methods ##############################################################################
 
     _command_description: (textParts...)->
-        @_rawData.text ?= ''
-        @_rawData.text += textParts.join ', '
+        @_rawData.description ?= ''
+        @_rawData.description += textParts.join ', '
 
     _command_officialUrl: (officialUrl)->
         if @_rawData.officialUrl? then throw new Error 'duplicate declaration of "officialUrl"'
         if officialUrl.length is 0 then throw new Error 'officialUrl cannot be empty'
         @_rawData.officialUrl = officialUrl
 
-    _command_video: (youTubeId, name)->
+    _command_video: (youTubeId, nameParts...)->
         if not youTubeId?.length then throw new Error 'video declaration requires a YouTubeID'
+        name = nameParts.join ', '
         if not name?.length then throw new Error 'video declaration requires a name'
 
         @_rawData.videos ?= []
@@ -40,6 +41,6 @@ module.exports = class ItemParserV1 extends CommandParserVersionBase
     # Object Building Methods ######################################################################
 
     _buildItem: (rawData, model)->
-        item.description = rawData.description if rawData.description
-        item.officialUrl = rawData.officialUrl if rawData.officialUrl
-        item.videos      = rawData.videos      if rawData.videos
+        model.description = rawData.description if rawData.description
+        model.officialUrl = rawData.officialUrl if rawData.officialUrl
+        model.videos      = rawData.videos      if rawData.videos