Fixed some typos in CONTRIBUTING.md
Fixed some typos in CONTRIBUTING.md

whackashoe/json,Newbrick/json,theodelrieu/json,stanmihai4/json,robertmrk/json,nlohmann/json,Newbrick/json,stanmihai4/json,kaidokert/json,hunter-packages/json,hunter-packages/json,stanmihai4/json,kaidokert/json,nlohmann/json,whackashoe/json,kaidokert/json,theodelrieu/json,nlohmann/json,hunter-packages/json,Newbrick/json