Update readme with .html => .mustache change
Update readme with .html => .mustache change

evilstreak/mustache,oelmekki/mustache,victormours/mustache,singy/mustache,thelazycamel/mustache,alloy/mustache,evilstreak/mustache,mustache/mustache,michael-gabenna/mustache,nuclearsandwich/mustache,wowteacher/mustache