I think we should make the best of this opportunity. While it is understandable that a guide for volunteers would most certainly include Getting started material for developers, technical writers, implementers, and other roles as proposed by a potential candidate but that would require a solid understanding of OpenMRS and would be a formidable task for a technical writer new to our community. However, if we have a proposal strong enough and a candidate who can complete the task within defined limit, I would love to see that guide is completed.
With that being said, a bird in hand is always better than the two in bushes. @rainbow has a clear task list to work on, the mentioned docs do need to be reviewed and by the end of GSoD2020, if we have them scrutinized properly, that would greatly help improve the documentation for developers and in turn, attract more developers for OpenMRS. I would be equally excited looking forward to @rainbow’s proposal as well.