Rework Using section

[cmgrote]

• [x] The developer guide needs to move under "Using" since it is for developers using Egeria - rather than Egeria contributors
• [ ] The link in "Build a connector" should point to the 'What is a connector" page in the developer guide.
• [x] The connector catalog should be here too rather than in its own section since choosing connectors is a key part of planning and administering. There are missing links for the runtime connectors.
• [ ] "Managing external identifiers" needs to be grouped with the descriptions of modelling types, deduplication, lineage etc. Grouped with concepts such as Anchors, Lineage etc on the Overview/Key Concepts page
• [ ] The CTS should be here under Using rather than in the Reference section - or part of the developer guide?

[adinhtdsibm]

@cmgrote Do you need any help here?

[mandy-chessell]

I am not sure where we are on moving the connector catalog but at the moment there is a lot of muddled content. It seems some of the OMRS design material (probably not relevant for this site) has been mixed with the connector catalog that is designed for the consumers of Egeria who may be selecting the connectors they need. I would be willing to try and untangle this - but need to make sure the OMRS design doc is restored into the main Egeria repository.