Unified versioning information and bumped version to 0.20.

Now we only need to change src/damaris/__init__.py and use dch -v
$VERSION to make a new version.

pyproject.toml

@@ -8,7 +8,7 @@ build-backend = "setuptools.build_meta"
 [project]
 requires-python = ">= 3.9"
 name = "python3-damaris"
-version = "0.19"
+dynamic = ["version"]
 description = "Python version 3 frontend for DAMARIS (DArmstadt MAgnetic Resonance Instrument Software)"
 license = {text = "GPL-2.0"}
 keywords = ["NMR", "data-processing"]
@@ -41,6 +41,9 @@ where = ["src"]
 [tool.setuptools.package-data]
 "damaris.gui" = ["DAMARIS3.png", "DAMARIS3.ico", "damaris.xml", "python.xml", "damaris3.glade"]
 
+[tool.setuptools.dynamic]
+version = {attr = "damaris.__version__"}
+
 [tool.setuptools.data-files]
 "share/python3-damaris/images" = ["src/damaris/gui/DAMARIS3.png", "src/damaris/gui/DAMARIS3.ico"]
 #"share/python3-damaris/doc" = ["doc/index.html"]