readme: use new logo
readme: use new logo

yuanwhy/tidb,gaocegege/tidb,EvilMcJerkface/tidb,pingcap/tidb,ngaut/tidb,silenceper/tidb,wusphinx/tidb,Nify/tidb,tiancaiamao/tidb,qiuyesuifeng/tidb,ngaut/tidb,8cbx/tidb,CodeRushing/tidb,8cbx/tidb,yangwenmai/tidb,andelf/tidb,CodeRushing/tidb,mccxj/tidb,yuanwhy/tidb,gaocegege/tidb,ming-relax/tidb,spongedu/tidb,Nify/tidb,ming-relax/tidb,kyle-wang/tidb,c4pt0r/tidb,pingcap/tidb,coocood/tidb,pingcap/tidb,kyle-wang/tidb,astaxie/tidb,qhsong/tidb,qiuyesuifeng/tidb,JinheLin/tidb,kyle-wang/tidb,c4pt0r/tidb,simon-xia/tidb,zimulala/tidb,pingcap/tidb,andelf/tidb,pingcap/tidb,zs634134578/tidb,coocood/tidb,yangwenmai/tidb,louishust/tidb,Cofyc/tidb,ngaut/tidb,wusphinx/tidb,simon-xia/tidb,JinheLin/tidb,myrice/tidb,c4pt0r/tidb,kyle-wang/tidb,c4pt0r/tidb,c4pt0r/tidb,qhsong/tidb,louishust/tidb,kyle-wang/tidb,XuHuaiyu/tidb,anywhy/tidb,ngaut/tidb,liyu4/tidb,cosmtrek/tidb,ueizhou/tidb,XuHuaiyu/tidb,kyle-wang/tidb,myrice/tidb,liyu4/tidb,pingcap/tidb,ngaut/tidb,silentred/tidb,spongedu/tidb,EvilMcJerkface/tidb,cosmtrek/tidb,ueizhou/tidb,anywhy/tidb,astaxie/tidb,zimulala/tidb,Cofyc/tidb,zs634134578/tidb,mccxj/tidb,silentred/tidb,tiancaiamao/tidb,c4pt0r/tidb,silenceper/tidb,ngaut/tidb