Update README for Border Router (#1851)
Update README for Border Router (#1851)


librasungirl/openthread,vaas-krish/openthread,vaas-krish/openthread,librasungirl/openthread,aeliot/openthread,jwhui/openthread,librasungirl/openthread,aeliot/openthread,openthread/openthread,gandreello/openthread,abtink/openthread,JakubBrachTieto/openthread,georgecpr/openthread,chshu/openthread,pvanhorn/openthread,JakubBrachTieto/openthread,fbsder/openthread,abtink/openthread,lanyuwen/openthread,fbsder/openthread,gandreello/openthread,lanyuwen/openthread,LeZhang2016/openthread,fbsder/openthread,gandreello/openthread,mszczodrak/openthread,vaas-krish/openthread,chshu/openthread,xiaom-GitHub/openthread,JakubBrachTieto/openthread,JakubBrachTieto/openthread,pvanhorn/openthread,mszczodrak/openthread,turon/openthread,fbsder/openthread,xiaom-GitHub/openthread,lanyuwen/openthread,erja-gp/openthread,LeZhang2016/openthread,openthread/openthread,LeZhang2016/openthread,georgecpr/openthread,openthread/openthread,erja-gp/openthread,xiaom-GitHub/openthread,georgecpr/openthread,aeliot/openthread,LeZhang2016/openthread,gandreello/openthread,chshu/openthread,vaas-krish/openthread,bukepo/openthread,pvanhorn/openthread,erja-gp/openthread,georgecpr/openthread,vaas-krish/openthread,erja-gp/openthread,turon/openthread,gandreello/openthread,LeZhang2016/openthread,mszczodrak/openthread,bukepo/openthread,fbsder/openthread,librasungirl/openthread,srickardti/openthread,mszczodrak/openthread,srickardti/openthread,fbsder/openthread,chshu/openthread,abtink/openthread,jwhui/openthread,turon/openthread,JakubBrachTieto/openthread,chshu/openthread,aeliot/openthread,srickardti/openthread,pvanhorn/openthread,pvanhorn/openthread,xiaom-GitHub/openthread,turon/openthread,mszczodrak/openthread,openthread/openthread,georgecpr/openthread,chshu/openthread,LeZhang2016/openthread,mszczodrak/openthread,pvanhorn/openthread,erja-gp/openthread,srickardti/openthread,JakubBrachTieto/openthread,lanyuwen/openthread,aeliot/openthread,lanyuwen/openthread,jwhui/openthread,gandreello/openthread,abtink/openthread,aeliot/openthread,bukepo/openthread,bukepo/openthread,erja-gp/openthread,vaas-krish/openthread,lanyuwen/openthread,jwhui/openthread,xiaom-GitHub/openthread,georgecpr/openthread,xiaom-GitHub/openthread