Support for cross-references

[lcawl]

🚀 Feature Proposal

This is probably more of a nice-to-have than a must-have.
There are often links/relationships/cross-references between our various APIs and properties. It would be nice to have a way to reference another API/object/property in our descriptions, such that we can ultimately render that as a link in our output.

Motivation

Cross-references that exist only as text are more likely to get out-dated (e.g. if API or property names change). It also requires the end-user to search for the referenced term instead of just following a link.

Example

Many of our API properties reference other properties, for example (potential cross-reference targets bolded):

• https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-create-index.html "wait_for_active_shards: ...Set to all or any positive integer up to the total number of shards in the index (number_of_replicas + 1)"
• https://www.elastic.co/guide/en/elasticsearch/reference/master/ml-put-job.html "categorization_analyzer: ...If categorization_field_name is specified, you can also define the analyzer that is used to interpret the categorization field. This property cannot be used at the same time as categorization_filters. The categorization analyzer specifies how the categorization_field is interpreted by the categorization process. The syntax is very similar to that used to define the analyzer in the Analyze endpoint..."
• https://www.elastic.co/guide/en/elasticsearch/reference/master/ml-put-datafeed.html "You must use Kibana, this API, or the create anomaly detection jobs API to create a datafeed..."

[lcawl]

Replaced by #2758