Add new Data section for CDP

[sreuland]

What problem does your feature solve?

No landing page for CDP exists yet on developer docs.

What would you like to see?

A new page hierarchy added for CDP under Developer Docs -> Data :

• Add a summary paragraph for CDP to Data landing page
  • CDP Introduction (use prior cdp blog intro for some ref/starting point) , explain the dual composition aspect of publishing with galexie and consuming with application pipelines.
  • CDP Deployment - Details on deploying Galexie, use the copy from services/galexie/README.md, and delete it from repo to avoid dup.

Make sure to use new 'Ledger metadata' term to refer to any instances of the LedgerCloseMeta, tx-meta, etc.

What alternatives are there?

[sreuland]

for CDP Development, there is a. build/learn article with copy on doing both export and consumer pipelines and may be able to use some of copy - https://developers.stellar.org/docs/category/build-custom-network-ingestion-pipeline

[urvisavla]

CDP Development - Explain how data pipeline arch is preferred for ingestion and how datastore of pre-computed ledger metadata provides the origin in a pipeline.
cover the go SDK packages that can be used for pipeline development: support/datastore to use GCSDataStore, ingest/ledgerbackend to use BufferedStorageBackend, ingest/cdp to use helper functions like PublishFromBufferedStorageBackend

As decided in the planning meeting, splitting this into a separate ticket