Updated the readme.md file and fixed the typo#45959

Farhan29-Dev wants to merge 1 commit intoibm-developer-skills-network:masteribm-developer-skills-network/jbbmo-Introduction-to-Git-and-GitHub:masterfrom

Farhan29-Dev:bug-fix-typoFarhan29-Dev/jbbmo-Introduction-to-Git-and-GitHub:bug-fix-typoCopy head branch name to clipboard