Suggestion: rename `rsconnect deploy api` command to `rsconnect deploy flask`

[SamEdwardes]

The rsconnect deploy command has the following options:

$ rsconnect deploy --help
Usage: rsconnect deploy [OPTIONS] COMMAND [ARGS]...

  Deploy content to Posit Connect, Posit Cloud, or shinyapps.io.

Options:
  --help  Show this message and exit.

Commands:
  api            Deploy a Python API to Posit Connect [v1.8.2+], Posit Cloud,
                 or shinyapps.io.
  bokeh          Deploy a Bokeh Application to Posit Connect [v1.8.4+], Posit
                 Cloud, or shinyapps.io.
  dash           Deploy a Dash Application to Posit Connect [v1.8.2+], Posit
                 Cloud, or shinyapps.io.
  fastapi        Deploy a Python FastAPI to Posit Connect [v2021.08.0+], Posit
                 Cloud, or shinyapps.io.
  html           Deploy html content to Posit Connect or Posit Cloud.
  manifest       Deploy content to Posit Connect, Posit Cloud, or shinyapps.io
                 by manifest.
  notebook       Deploy Jupyter notebook to Posit Connect [v1.7.0+].
  other-content  Describe deploying other content to Posit Connect.
  quarto         Deploy Quarto content to Posit Connect [v2021.08.0+] or Posit
                 Cloud.
  shiny          Deploy a Python Shiny Application to Posit Connect
                 [v2022.07.0+], Posit Cloud, or shinyapps.io.
  streamlit      Deploy a Streamlit Application to Posit Connect [v1.8.4+],
                 Posit Cloud, or shinyapps.io.
  voila          Deploy Jupyter notebook in Voila mode to Posit Connect
                 [v2023.03.0+].

I propose renaming rsconnect deploy api to rsconnect deploy flask.

• Now that FastAPI is supported, it is confusing that the command to deploy a flask API is called api (all of the other deploy commands use the framework name).
• The help message is also confusing and does not mention Flask (e.g. Deploy a Python API to Posit Connect [v1.8.2+], Posit Cloud, or shinyapps.io.. It is unclear to users what a "Python API" is.
• This can be done so that backwards compatibility is not broken, but we only document and recommend rsconnect deploy flask.

[wydsith]

If we're renaming anyway - do we want to move away from rs(rstudio)connect and move towards the new acronyms?