Added readme for the build system.
Added readme for the build system.

JulianVolodia/syntaxhighlighter,younisd/syntaxhighlighter,rackerlabs/SyntaxHighlighter,Adai0808/syntaxhighlighter,zygzyp/syntaxhighlighter,whouses/syntaxhighlighter,norux/syntaxhighlighter,DustinH/syntaxhighlighter,glabcn/syntaxhighlighter,nullice/syntaxhighlighter,glabcn/syntaxhighlighter,wang508x102/syntaxhighlighter,syntaxhighlighter/syntaxhighlighter,rackerlabs/SyntaxHighlighter,syntaxhighlighter/syntaxhighlighter,Adai0808/syntaxhighlighter,raviji/syntaxhighlighter,JungMinu/syntaxhighlighter,rackerlabs/SyntaxHighlighter,raviji/syntaxhighlighter,liuxulei/syntaxhighlighter,tgckpg/BotanJS-SyntaxHighlighter,DustinH/syntaxhighlighter,whouses/syntaxhighlighter,norux/syntaxhighlighter,zygzyp/syntaxhighlighter,2947721120/syntaxhighlighter,rackerlabs/SyntaxHighlighter,2947721120/syntaxhighlighter,jonesgithub/syntaxhighlighter,nullice/syntaxhighlighter,younisd/syntaxhighlighter,liuxulei/syntaxhighlighter,JungMinu/syntaxhighlighter,JulianVolodia/syntaxhighlighter,wang508x102/syntaxhighlighter,jonesgithub/syntaxhighlighter