Update copyright year in README.md#25

TrevorSA123 wants to merge 1 commit intoibm-developer-skills-network:mainibm-developer-skills-network/mcino-Introduction-to-Git-and-GitHub:mainfrom

TrevorSA123:bug-fix-typoTrevorSA123/mcino-Introduction-to-Git-and-GitHub:bug-fix-typoCopy head branch name to clipboard