Improve setup.cfg minimum version documentation

- version: a960ee1c
- project_urls: df224644

docs/setuptools.txt

@@ -2475,10 +2475,10 @@ Metadata
 Key                             Aliases            Type               Minumum Version
 ==============================  =================  =================  ===============
 name                                               str
-version                                            attr:, file:, str
+version                                            attr:, file:, str  39.2.0
 url                             home-page          str
 download_url                    download-url       str
-project_urls                                       dict
+project_urls                                       dict               38.3.0
 author                                             str
 author_email                    author-email       str
 maintainer                                         str
@@ -2503,9 +2503,9 @@ obsoletes                                          list-comma
 Options
 -------
 
-=======================  ===================================  =====
+=======================  ===================================  ===============
 Key                      Type                                 Minimum Version
-=======================  ===================================  =====
+=======================  ===================================  ===============
 zip_safe                 bool
 setup_requires           list-semi
 install_requires         list-semi
@@ -2528,7 +2528,7 @@ exclude_package_data     section
 namespace_packages       list-comma
 py_modules               list-comma
 data_files               dict                                 40.5.0
-=======================  ===================================  =====
+=======================  ===================================  ===============
 
 .. note::