README.md: add supported Qt bindings

Author: PierreRaybaut

README.md

@@ -11,14 +11,9 @@
 
 ![PythonQwt Test Launcher](https://raw.githubusercontent.com/PlotPyStack/PythonQwt/master/qwt/tests/data/testlauncher.png)
 
-The `PythonQwt` project was initiated to solve -at least temporarily- the
-obsolescence issue of `PyQwt` (the Python-Qwt C++ bindings library) which is
-no longer maintained. The idea was to translate the original Qwt C++ code to
-Python and then to optimize some parts of the code by writing new modules
-based on NumPy and other libraries.
+The `PythonQwt` project was initiated to solve -at least temporarily- the obsolescence issue of `PyQwt` (the Python-Qwt C++ bindings library) which is no longer maintained. The idea was to translate the original Qwt C++ code to Python and then to optimize some parts of the code by writing new modules based on NumPy and other libraries.
 
-The `PythonQwt` package consists of a single Python package named `qwt` and
-of a few other files (examples, doc, ...).
+The `PythonQwt` package consists of a single Python package named `qwt` and of a few other files (examples, doc, ...).
 
 See documentation [online](https://pythonqwt.readthedocs.io/en/latest/) or [PDF](https://pythonqwt.readthedocs.io/_/downloads/en/latest/pdf/) for more details on the library and [changelog](CHANGELOG.md) for recent history of changes.
 
@@ -71,19 +66,13 @@ PythonQwt-tests --mode unattended
 
 ## Overview
 
-The `qwt` package is a pure Python implementation of `Qwt` C++ library with
-the following limitations.
+The `qwt` package is a pure Python implementation of `Qwt` C++ library with the following limitations.
 
-The following `Qwt` classes won't be reimplemented in `qwt` because more
-powerful features already exist in `guiqwt`: `QwtPlotZoomer`,
-`QwtCounter`, `QwtEventPattern`, `QwtPicker`, `QwtPlotPicker`.
+The following `Qwt` classes won't be reimplemented in `qwt` because more powerful features already exist in `guiqwt`: `QwtPlotZoomer`, `QwtCounter`, `QwtEventPattern`, `QwtPicker`, `QwtPlotPicker`.
 
-Only the following plot items are currently implemented in `qwt` (the only
-plot items needed by `guiqwt`): `QwtPlotItem` (base class), `QwtPlotItem`,
-`QwtPlotMarker`, `QwtPlotSeriesItem` and `QwtPlotCurve`.
+Only the following plot items are currently implemented in `qwt` (the only plot items needed by `guiqwt`): `QwtPlotItem` (base class), `QwtPlotItem`, `QwtPlotMarker`, `QwtPlotSeriesItem` and `QwtPlotCurve`.
 
-See "Overview" section in [documentation](https://pythonqwt.readthedocs.io/en/latest/)
-for more details on API limitations when comparing to Qwt.
+See "Overview" section in [documentation](https://pythonqwt.readthedocs.io/en/latest/) for more details on API limitations when comparing to Qwt.
 
 ## Roadmap
 
@@ -94,21 +83,31 @@ The `qwt` package short-term roadmap is the following:
 - [X] Replace `setup.py` by `pyproject.toml`, using `setuptools` (e.g. see `guidata`)
 - [ ] Add more unit tests: the ultimate goal is to reach 90% code coverage
 
-## Dependencies
+## Dependencies and installation
+
+### Supported Qt versions and bindings
+
+The whole PlotPyStack set of libraries relies on the [Qt](https://doc.qt.io/) GUI toolkit, thanks to [QtPy](https://pypi.org/project/QtPy/), an abstraction layer which allows to use the same API to interact with different Python-to-Qt bindings (PyQt5, PyQt6, PySide2, PySide6).
+
+Compatibility table:
+
+| PythonQwt version | PyQt5 | PyQt6 | PySide2 | PySide6 |
+|-------------------|-------|-------|---------|---------|
+| 0.16 and earlier  | ✅    | ⚠️    | ❌     | ⚠️      |
+| Latest            | ✅    | ✅    | ❌     | ✅      |
 
 ### Requirements
 
 - Python >=3.8
-- PyQt5, PyQt6 or PySide6
-- QtPy >= 1.3
+- QtPy >= 1.3 (and a Python-to-Qt binding library, see above)
 - NumPy >= 1.5
 
 ### Optional dependencies
 
 - coverage, pytest (for unit tests)
 - sphinx (for documentation generation)
 
-## Installation
+### Installation
 
 From the source package:
 
@@ -121,27 +120,16 @@ python -m build
 ### Main code base
 
 - Copyright © 2002 Uwe Rathmann, for the original Qwt C++ code
-- Copyright © 2015 Pierre Raybaut, for the Qwt C++ to Python translation and
-optimization
-- Copyright © 2015 Pierre Raybaut, for the PythonQwt specific and exclusive
-Python material
-
-### PyQt, PySide and Python2/Python3 compatibility modules
-
-- Copyright © 2009-2013 Pierre Raybaut
-- Copyright © 2013-2015 The Spyder Development Team
+- Copyright © 2015 Pierre Raybaut, for the Qwt C++ to Python translation and optimization
+- Copyright © 2015 Pierre Raybaut, for the PythonQwt specific and exclusive Python material
 
 ### Some examples
 
 - Copyright © 2003-2009 Gerard Vermeulen, for the original PyQwt code
-- Copyright © 2015 Pierre Raybaut, for the PyQt5/PySide port and further
-developments (e.g. ported to PythonQwt API)
+- Copyright © 2015 Pierre Raybaut, for the PyQt5/PySide port and further developments (e.g. ported to PythonQwt API)
 
 ## License
 
-The `qwt` Python package was partly (>95%) translated from Qwt C++ library:
-the associated code is distributed under the terms of the LGPL license. The
-rest of the code was either wrote from scratch or strongly inspired from MIT
-licensed third-party software.
+The `qwt` Python package was partly (>95%) translated from Qwt C++ library: the associated code is distributed under the terms of the LGPL license. The rest of the code was either wrote from scratch or strongly inspired from MIT licensed third-party software.
 
 See included [LICENSE](LICENSE) file for more details about licensing terms.