address some comments

Author: backmari

INSTALL.md

@@ -3,7 +3,7 @@
 Whether you're installing SasView to use as a tool for your research or
 because you're wanting to work on the code, it is recommended that you
 work inside a Python virtual environment of some sort.
-A `venv` or a `conda` are both popular choices.
+A `venv` or a `Pixi` are both popular choices.
 
 ## Installing SasView as a User
 
@@ -94,8 +94,7 @@ debugging software, e.g.:
 An alternative to `venv` is the package management tool Pixi. If Pixi is not
 installed, follow the instructions [here](https://pixi.prefix.dev/latest/#installation).
 
-To start developing using Pixi, download the repos and enter the shell into
-the development environment:
+The very quick version for developing using Pixi is:
 
 ```shell
 # Clone the repository
@@ -109,7 +108,7 @@ cd sasview
 pixi shell
 
 # Start the GUI
-sasview
+python -m sas
 
 # Run tests
 pixi run test
@@ -118,8 +117,29 @@ pixi run test
 exit
 ```
 
-Note that `sasdata`, `sasmodels` and `sasview` are installed in editable mode,
-meaning that any changes are immediately available during development.
+In more detail, the steps are:
+
+1. Obtain the SasView source using `git`. You will likely need to coordinate
+   updates to `sasdata` and `sasmodels`. The
+   [`bumps`](https://github.com/bumps/bumps) and
+   [`periodictable`](https://github.com/python-periodictable/periodictable)
+   packages are far more loosely coupled, but depending on what you are
+   doing you may also want them as development packages, in which case they
+   need to be added as editable in the section `[tool.pixi.pypi-dependencies]`
+   in `pyproject.toml`.
+1. Create (or reuse) a local Pixi environment in `.pixi` and enter the shell
+   into the developer environment. The first time it will take a while to
+   download and unpack all dependencies.
+   Note that `sasdata`, `sasmodels` and `sasview` are installed in editable mode,
+   meaning that any code changes will be available the next time you run the
+   program.
+1. Run SasView! As an alternative to typing `python -m sas`, you can simply
+   type `sasview`.
+
+Almost all the modules that SasView needs are available as precompiled modules
+on PyPI, including numpy, scipy, h5py, pyside6. A handful of Python-only
+modules will be built into wheels on your local machine. Installing the
+dependencies should be a one-off task.
 
 ## Pre-Commit Hooks for Linting