Doc: Production/Stable (#488)

* Doc: Production/Stable

Remove mention of "beta" status.
Although all actively developed modeling codes are constantly
in development, the "beta" flag can be removed by now and will
avoid to scare away uers.

* Apply suggestions from code review

README.md

@@ -6,7 +6,6 @@
 [![Supported Platforms](https://img.shields.io/badge/platforms-linux%20|%20osx%20|%20win-blue)](https://impactx.readthedocs.io/en/latest/install/users.html)  
 [![DOI (source)](https://img.shields.io/badge/DOI%20(source)-10.5281/zenodo.6954922-blue.svg)](https://doi.org/10.5281/zenodo.6954922)
 [![DOI (paper)](https://img.shields.io/badge/DOI%20(paper)-10.18429%2FJACoW--NAPAC2022--TUYE2-blue.svg)](https://doi.org/10.18429/JACoW-NAPAC2022-TUYE2)  
-[![Development Status](https://img.shields.io/badge/development%20status-beta-orange.svg)](https://en.wikipedia.org/wiki/Software_release_life_cycle)
 [![Language: C++17](https://img.shields.io/badge/language-C%2B%2B17-orange.svg)](https://isocpp.org/)
 [![Language: Python](https://img.shields.io/badge/language-Python-orange.svg)](https://python.org/)
 

docs/source/index.rst

@@ -6,11 +6,7 @@ ImpactX
 ImpactX is an s-based beam dynamics code including space charge effects.
 This is the next generation of the `IMPACT-Z <https://github.com/impact-lbl/IMPACT-Z>`__ code.
 
-.. note::
-
-   ImpactX development is in `beta status <https://en.wikipedia.org/wiki/Software_release_life_cycle>`__.
-   Please contact us with any questions on it or if you like to contribute to its development.
-
+Please contact us with any questions on it or if you like to contribute to its development.
 
 .. _contact:
 

setup.py

@@ -271,7 +271,7 @@ def build_extension(self, ext):
     # cmdclass={'test': PyTest},
     # platforms='any',
     classifiers=[
-        "Development Status :: 4 - Beta",
+        "Development Status :: 5 - Production/Stable",
         "Natural Language :: English",
         "Environment :: Console",
         "Environment :: GPU",