[docs]: New docs section for interacting with a node / update of "Interface" section

[clevinson]

• docs: Add new section "Running a Node" #7701 new page for running a node / booting up localnet (including genesis & keybase) (@amaurymartiny )

  • Related: update run-node.md to use starport #7403 quick-start.md
  • Related: document how to create a new key type and add it to the keyring #6500

• docs: Add new section "Running a Node" #7701 new page for CLI interactions

• docs: Add grpc & rest endpoints overview #8064 new page for generic gRPC endpoints (@amaurymartiny)

  • Add doc to use gRPC to query at a certain block height
  • grpc reflection

• Create docs for signing & broadcasting txs #8257 new page for Tx Generating, Signing & broadcasting @amaurymartiny

  • Add example for simulating Tx
  • update TODO links in "interact with a node" docs: Add grpc & rest endpoints overview #8064 (comment)
  • Update TODO links in "Core Concepts", Update "Core Concepts" docs #7948 (comment), Update "Core Concepts" docs #7948 (comment)
  • Update TODO links in "Migrations", docs: Add REST endpoints migration guide #8011 (comment)

• docs: Add grpc & rest endpoints overview #8064 Change title, maybe "Running a Node, API and CLI"

Notes:

• remove mention of handler and only use the Msg service vocabulary.

[clevinson]

NOTE: We many need to update the links in deprecation headers when this is done (or possibly link to client migration guides if that's better suited)