updated dev guidelines to clarify fork requirement

[joseriyancyriac]

• Updated the docs/guidelines/development.rst file to specify that the StoglRobotics-forks organization contains only forks of 3rd party public repositories.
• This change clarifies the nature of the repositories in the organization, ensuring that it's understood they are exclusively third-party forks and not original Stogl Robotics repositories.
• Also, integrated RST syntax for typographically correct superscript in '3rd'.