Updated footer in README.md#37191

Stephen1k wants to merge 1 commit intoibm-developer-skills-network:masteribm-developer-skills-network/jbbmo-Introduction-to-Git-and-GitHub:masterfrom

Stephen1k:bug-fix-typoStephen1k/jbbmo-Introduction-to-Git-and-GitHub:bug-fix-typoCopy head branch name to clipboard