README.md: Add jonchang to maintainer list
README.md: Add jonchang to maintainer list

Signed-off-by: Bob W. Hogg <c772a964fd55352a3510e5d535dd9ccc9ac30168@linux.com>

rwhogg/brew,maxim-belkin/brew,hanxue/linuxbrew,rwhogg/brew,hanxue/linuxbrew,rwhogg/brew,maxim-belkin/brew,Linuxbrew/brew,Linuxbrew/brew,Linuxbrew/brew,Linuxbrew/brew,maxim-belkin/brew,hanxue/linuxbrew