Fix a minor grammatical mistake on themes' document
Fix a minor grammatical mistake on themes' document

chrisfinazzo/jekyll,tillgrallert/jekyll,gencer/jekyll,tomjohnson1492/jekyll,gencer/jekyll,tillgrallert/jekyll,tomjohnson1492/jekyll,Strangehill/jekyll,alex-kovac/jekyll,getandpost/jekyll.github.io,gencer/jekyll,Strangehill/jekyll,jekyll/jekyll,jekyll/jekyll,ryanshaw/jekyll,rasa2011/rasa2011.github.io,rlugojr/jekyll,rlugojr/jekyll,jaybe-jekyll/jekyll,tomjohnson1492/jekyll,yhironaka/yhironaka.github.io,Strangehill/jekyll,xiebinhqy/jklly_china,Strangehill/jekyll,ryanshaw/jekyll,x-way/jekyll,rlugojr/jekyll,chrisfinazzo/jekyll,tomjohnson1492/jekyll,jaybe-jekyll/jekyll,jekyll/jekyll,x-way/jekyll,tomjohnson1492/jekyll,fulldecent/jekyll,rlugojr/jekyll,jaybe-jekyll/jekyll,tillgrallert/jekyll,alex-kovac/jekyll,rasa2011/rasa2011.github.io,getandpost/jekyll.github.io,gencer/jekyll,fulldecent/jekyll,gencer/jekyll,xiebinhqy/jklly_china,getandpost/jekyll.github.io,x-way/jekyll,chrisfinazzo/jekyll,chrisfinazzo/jekyll,ryanshaw/jekyll,alex-kovac/jekyll,rasa2011/rasa2011.github.io,alex-kovac/jekyll,xiebinhqy/jklly_china,tillgrallert/jekyll,tillgrallert/jekyll,Strangehill/jekyll,fulldecent/jekyll,fulldecent/jekyll,jekyll/jekyll,alex-kovac/jekyll,x-way/jekyll,ryanshaw/jekyll,jaybe-jekyll/jekyll,xiebinhqy/jklly_china