Chore: put connection config link in a separate line

[georgesittas]

Small change to get configs to look like this instead of having a single big comment for the config connection link. Added another link to the base connection configs because they're missing from individual connection pages.

gateways:
  dev:
    connection:
      # For more information on configuring the connection to your execution engine, visit:
      # https://sqlmesh.readthedocs.io/en/stable/reference/configuration/#connections
      # https://sqlmesh.readthedocs.io/en/stable/integrations/engines/duckdb/#connection-options
      type: duckdb
      # concurrent_tasks: 1
      # register_comments: True
      # pre_ping: 
      # pretty_sql: 
      # database: 
      # catalogs: 
      # extensions: 
      # connector_config: 
      # token: 


default_gateway: dev

model_defaults:
  dialect: duckdb
  start: 2025-01-30

[VaggelisD]

This is better UX, thanks!