Update mention of tweaks.php in README.md
Update mention of tweaks.php in README.md

I first thought my download was broken, but I believe this file is no longer in use.
jchck/jchck_,SparkartGroupInc/nadando,andbaz/launchbaz,solidusjs/wp-solidus,andbaz/launchbaz,carl-alberto/business-portfolio,vaishaliagola27/_s,jchck/jchck_,vaishaliagola27/_s,vaishaliagola27/_s,madeso-uk/vcsassist,carl-alberto/business-portfolio,madeso-uk/vcsassist