Update PR guide and add a "short" version
Update PR guide and add a "short" version

RonnyPfannschmidt/pytest,davidszotten/pytest,tomviner/pytest,markshao/pytest,The-Compiler/pytest,alfredodeza/pytest,tomviner/pytest,nicoddemus/pytest,hackebrot/pytest,txomon/pytest,nicoddemus/pytest,rmfitzpatrick/pytest,pfctdayelise/pytest,ddboline/pytest,Akasurde/pytest,pytest-dev/pytest,MichaelAquilina/pytest,tareqalayan/pytest,The-Compiler/pytest