Ensure default-editor subpackage is easily swappable

This change makes it so that the nano-default-editor package
Provides system-default-editor and Conflicts with system-default-editor.

With this setup, RPM will ensure that only one instance of system-default-editor
will be installed at a time, guaranteeing that the default editor is sanely
set.

nano.spec

@@ -1,7 +1,7 @@
 Summary:         A small text editor
 Name:            nano
 Version:         5.3
-Release:         2%{?dist}
+Release:         3%{?dist}
 License:         GPLv3+
 URL:             https://www.nano-editor.org
 Source:          https://www.nano-editor.org/dist/latest/%{name}-%{version}.tar.xz
@@ -28,6 +28,9 @@ GNU nano is a small and friendly text editor.
 %package default-editor
 Summary:         Sets GNU nano as the default editor
 Requires:        nano = %{version}-%{release}
+# Ensure that only one package with this capability is installed
+Provides:        system-default-editor
+Conflicts:       system-default-editor
 BuildArch:       noarch
 
 %description default-editor
@@ -92,6 +95,9 @@ install -Dpm 0644 %{SOURCE13} %{buildroot}%{_datadir}/fish/vendor_conf.d/%{basen
 
 
 %changelog
+* Mon Oct 12 2020 Neal Gompa <ngompa13@gmail.com> - 5.3-3
+- Ensure default-editor subpackage is easily swappable
+
 * Thu Oct 08 2020 Neal Gompa <ngompa13@gmail.com> - 5.3-2
 - Enable all extra definitions for syntax highlighting (#1886561)