Dear @Thierryvm,
Thanks mentioning me in your project, unfortunately I am not able to assign time the coming months, far to many un-finished projects, private arrangements and the summer holiday.
There is already so much valuable input, I would just like to share some different perspectives to consider in benefit for your project.
When I started Coda, I had the same feeling to put everything in one document, as you will learn it’s not necessarily always the best to do, especially to content that doesn’t relate to one or the other.
Therefore an overarching “doc/wiki” that contains a structure with links and metadata to search for criteria would be a more workable. To add there a section for voting would be great, and downvoting should only be possible if the voter offers a better proposal to improve the work.
This structure to be located in a separate workspace, where you can add others with admin rights, editors and for the audience to view the docs and the actual samples, study material to be able to copy.
Metadata to be used could be #formulas, #beginner, #medium, #advanced, #Fundamentals, #table structures and whatever comes up during the development.
Let the interested submit samples through a form and when the content has been approved it can be added by the moderators with the appropriate rights. When an application can’t be added it will be good to inform the submitter why and give the possibility to update.
This all is an serious task and would take many man hours.
Who knows Coda is able to assign resources for development in this direction. Of course there are already several initiatives and the content makers should consider to unite and made visible / promoted through one channel, the “market” (users interested in Coda) will decide what works for them or not.