Add more instructions to install pyjs-code-runner (#11)

* Add more instructions to install `pyjs-code-runner`

* Add repo URL

* Add run example

Author: jtpio

README.md

@@ -1,26 +1,65 @@
 # pyjs-code-runner
+
 [![CI](https://github.com/emscripten-forge/pyjs-code-runner/actions/workflows/main.yaml/badge.svg)](https://github.com/emscripten-forge/pyjs-code-runner/actions/workflows/main.yaml)
 
 A driver to run python code in a wasm environment, almost like running vanilla python code.
 
 ## Motivation
 
-Debugging, experimenting and testing python code from a dedicated conda environment 
+Debugging, experimenting and testing python code from a dedicated conda environment
 in browser environment is a complex process with a lot of (complicated) steps.
 
-* create the environment for emscripten 
+* create the environment for emscripten
 * pack the environemtn
 
+## Installation
+
+Currently `pyjs-code-runner` is not available on PyPI. To install it, clone the repository and install it with `pip`:
+
+We first recommend to create a new conda environment for `pyjs-code-runner`:
+
+```bash
+mamba create -n pyjs-code-runner -c conda-forge python
+mamba activate pyjs-code-runner
+```
+
+Then install `pyjs-code-runner`:
+
+```bash
+git clone https://github.com/emscripten-forge/pyjs-code-runner
+cd pyjs-code-runner
+python -m pip install -e .
+```
+
+Then install the browser for use with Playwright:
+
+```bash
+playwright install
+```
+
+You will then need another conda environment for the code you want to run in the browser. Here we specify the `emscripten-forge` channel and the `emscripten-32` platform:
 
+```bash
+mamba create -n my_env -c https://repo.mamba.pm/emscripten-forge -c https://repo.mamba.pm/conda-forge --platform=emscripten-32 python numpy pyjs
+```
+
+You might want to add more dependencies to this environment, depending on the code you would like to run.
+
+## Usage
 
-## Examples
+Here we assume a file `main.py` located at `~/foo/bar/main.py` with the following content:
 
+```py
+import numpy as np
 
+print("Hello from pyjs-code-runner")
+print("numpy version:", np.__version__)
+```
 
-Here we assume a file `main.py` located at `~/foo/bar/main.py`.
+You can then run this code in the browser with the following command:
 
 ```bash
-# run in browser-main-thread backend 
+# run in browser-main-thread backend
 pyjs_code_runner run script                                                                \
     browser-main                                                                           \
     --conda-env     ~/micromamba/envs/my_env         `# the emscripten-forge env`          \
@@ -37,12 +76,40 @@ pyjs_code_runner run script
                                                                                            \
     --async-main                                     `# should a top-level async`          \
                                                      `# function named main be called`     \
-    --headless 
+    --headless
 
 ```
 
+The `--headless` flag will run the browser in headless mode. If you want to see the browser open on your machine, you can remove this flag.
+
+When you run this command you swill be able to see the output of the code in the terminal that looks like the following:
+
 ```bash
-# run in browser-worker-thread backend 
+Failed to load resource: the server responded with a status of 404 (File not found)
+fetching python package from ./python-3.10.2-h_hash_26_cpython.tar.gz
+fetching pkg numpy from ./numpy-1.24.2-py310h6d2fff6_0.tar.gz
+fetching pkg pip from ./pip-23.1-pyhd8ed1ab_0.tar.gz
+fetching pkg setuptools from ./setuptools-63.4.2-py310h8bed8af_0.tar.gz
+fetching pkg wheel from ./wheel-0.40.0-pyhd8ed1ab_0.tar.gz
+fetching pkg pyparsing from ./pyparsing-3.0.9-pyhd8ed1ab_0.tar.gz
+fetching pkg pyjs from ./pyjs-1.0.0-hc96583f_0.tar.gz
+fetching pkg emscripten-abi from ./emscripten-abi-3.1.27-hb0f4dca_5.tar.gz
+extract /package_tarballs/setuptools-63.4.2-py310h8bed8af_0.tar.gz (304 bytes)
+extract /package_tarballs/wheel-0.40.0-pyhd8ed1ab_0.tar.gz (51524 bytes)
+extract /package_tarballs/pyparsing-3.0.9-pyhd8ed1ab_0.tar.gz (90256 bytes)
+extract /package_tarballs/pyjs-1.0.0-hc96583f_0.tar.gz (283 bytes)
+extract /package_tarballs/emscripten-abi-3.1.27-hb0f4dca_5.tar.gz (302 bytes)
+extract /package_tarballs/pip-23.1-pyhd8ed1ab_0.tar.gz (1319563 bytes)
+extract /package_tarballs/python-3.10.2-h_hash_26_cpython.tar.gz (2279530 bytes)
+extract /package_tarballs/numpy-1.24.2-py310h6d2fff6_0.tar.gz (3594626 bytes)
+Hello from pyjs-code-runner
+numpy version: 1.24.2
+```
+
+There are other ways to run the code, for example in a worker thread:
+
+```bash
+# run in browser-worker-thread backend
 # in a headless fashion
 pyjs_code_runner run script \
     browser-worker \
@@ -51,8 +118,5 @@ pyjs_code_runner run script \
     --script        main.py \
     --work-dir      /tests \
     --async-main           \
-    --headless          
-
-```
-
-
+    --headless
+```