Firstly we would discuss this with stakeholders to understand the exact requirements and if there are any preferences. 
Having said that, some ideas would be:
 - Using a Github repository where anyone could contribute and create a pull request. The administrator would then approve the pull request and merge it, making the content officially viewable on our platform. Advantages: easy to do from a dev perspective, fully transparent and open to anyone. Disadvantages: would require some documentation (text/videos/walk thrus) for people to follow. Not impossible (it has been done before for other services), just a little bit more friction initially.
 - Using a survey/form tool such as Google Forms or Typeform. Anyone could submit a form, administrator would review entries, then submit approved entries to another document (e.g. Google Sheets). The approved entries would automatically be indexed and appear as part of the official information. Advantages: easy for anyone to follow. Disadvantages: is not very open/transparent, people may see it as unfair if they get rejected with no feedback, people can't learn from other's mistakes.
 - Custom system. If this is a core problem that needs to be solved, then a custom system could be created for this, however it would add costs and time, so may not be worth it for this particular RFP.