update README

Author: O957

README.md

@@ -2,28 +2,34 @@
 
 ⚠️ This is a work in progress.
 
-_`pyrenew-flu-light` is an instantiation of an [Epidemia](https://imperialcollegelondon.github.io/epidemia/) influenza forecasting model in [PyRenew](https://github.com/CDCgov/PyRenew)._
+_`pyrenew-flu-light` is an influenza forecasting model (originally written in `R`, using the package [Epidemia](https://imperialcollegelondon.github.io/epidemia/), with the name `cfaepim`) that has been re-instantiated via [PyRenew](https://github.com/CDCgov/PyRenew)._
 
-NOTE: Presently, this `pyrenew-flu-light` cannot be installed and used with current NHSN, as its author is validating it on historical influenza data.
+NOTE: Presently, this `pyrenew-flu-light` cannot be installed and used with current NHSN data.
 
-Run command typically used:
+## Usage
+
+PFL (`pyrenew-flu-light`) can be used in two modes: "active" and "historical". The "active" mode uses respiratory incidence data sourced from available API frameworks whereas the "historical" mode relies on saved dataset snapshots (currently, these snapshots are from the 2023-24 NHSN data, and were generated by `cfaepim` code).
+
+Before running PFL, installing `poetry` and creating a virtual environment will very likely be necessary. This can be first done via `pipx install poetry` (see [Poetry](https://python-poetry.org/docs/) website for more information) and then, to create the environment, `poetry install` followed by `poetry shell` in the PFL folder (only done after cloning: `git clone https://github.com/CDCgov/pyrenew-flu-light`).
+
+After `poetry shell` has been run, then to use the "historical" mode (once within the folder `pyrenew_flu_light`), the `run.py` file creates an _experiment_. Each experiment generates forecasts based on selected jurisdictions and a configuration file. The configuration files for the "historical" mode are derived from the configuration files used in `cfaepim`; the reader will most often never need to worry about configuration files in the "historical" mode. To run:
 
 ```
-poetry run python tut_epim_port_msr.py --reporting_date 2024-01-20 --regions NY --historical --forecast
+poetry run python run.py --reporting_date 2024-01-20 --regions NY,AL,CA --historical --forecast --exp_name experiment_01
 
-python3 tut_epim_port_msr.py --reporting_date 2024-01-20 --regions NY --historical --forecast
+poetry run python run.py --reporting_date 2024-03-30 --regions not:NY,AL,CA --historical --forecast --exp_name experiment_02
 ```
 
 ## ...Contained Within This Repository
 
 
-- [x] An Apache 2.0 license
-- [x] An issue template (taken from PyRenew)
 - [ ] A pull request template
-- [x] A `pre-commit` schema
-- [x] A `.gitignore` file (taken from PyRenew)
-- [ ] A website
-- [ ] Formal contribution language (hybrid, from `cdcent`)
+- [ ] A website.
+- [x] An Apache 2.0 license
+- [x] An issue template (taken from PyRenew).
+- [x] A `pre-commit` schema.
+- [x] A `.gitignore` file (taken from PyRenew).
+- [x] Formal contribution language (hybrid, from `cdcent`)
 
 
 ## CDCGov & Disclaimers, Notices, And Code Of Conduct