doc/site/classes.markdown: add static fields example
doc/site/classes.markdown: add static fields example

Nave-Neel/wren,bigdimboom/wren,Rohansi/wren,munificent/wren,Rohansi/wren,foresterre/wren,Nave-Neel/wren,munificent/wren,minirop/wren,Nelarius/wren,Nelarius/wren,Nelarius/wren,minirop/wren,munificent/wren,foresterre/wren,Nelarius/wren,Rohansi/wren,foresterre/wren,minirop/wren,munificent/wren,foresterre/wren,Nave-Neel/wren,bigdimboom/wren,minirop/wren,Rohansi/wren,Nelarius/wren,Nave-Neel/wren,bigdimboom/wren,munificent/wren,bigdimboom/wren,foresterre/wren,munificent/wren,minirop/wren