Host searchable knowledgebase holding all InvenioRDM communications

[saragon02]

Ideas:

• Add a KB page to inveniosoftware.org (updates to website as part of Documentation IG): should enable website to feature sections holding important documentation & updates
• Establish InvenioRDM Zenodo Community for important outputs

Create based on examples:

• Provide examples of knowledgebases from other software projects #83