Unify badge style (#1849)
Unify badge style (#1849)

The "PRs Welcome" badge in README.md was flat-styled.  Change to the default style of all other badges in the README file

forslund/mycroft-core,Dark5ide/mycroft-core,linuxipho/mycroft-core,linuxipho/mycroft-core,MycroftAI/mycroft-core,forslund/mycroft-core,Dark5ide/mycroft-core,MycroftAI/mycroft-core