Add PPA support (#880)

* Clean up a few things in various setup function
* Add Launchpad-related setting to Debian build function
* Add signature feature to package builder and fix error in debian/copyright
* Update documentation
* Update README

docs/source/index.rst

@@ -4,7 +4,7 @@ novelWriter |release|
 
 .. only:: html
 
-   .. image:: https://github.com/vkbo/novelWriter/workflows/python%203.8/badge.svg?branch=main
+   .. image:: https://github.com/vkbo/novelWriter/actions/workflows/test_linux.yml/badge.svg?branch=main
       :target: https://github.com/vkbo/novelWriter/actions
       :alt: Python Tests
 
@@ -12,10 +12,6 @@ novelWriter |release|
       :target: https://codecov.io/gh/vkbo/novelWriter
       :alt: Code Coverage
 
-   .. image:: https://readthedocs.org/projects/novelwriter/badge/?version=latest
-      :target: https://novelwriter.readthedocs.io/en/latest/?badge=latest
-      :alt: Documentation
-
    .. image:: https://img.shields.io/github/v/release/vkbo/novelwriter
       :target: https://github.com/vkbo/novelWriter/releases
       :alt: GitHub Release
@@ -47,8 +43,8 @@ too. novelWriter can be run directly from the Python source, installed from the
 
 You can also download a minimal archive package of novelWriter tailored for your operating system.
 This package can be extracted anywhere on your computer, and a setup script can be run to create
-the necessary icons and file associations. See :ref:`a_started`, or one or the setup instructions
-for your operating system for further details.
+the necessary icons and file associations. See the setup instructions for your operating system for
+further details.
 
 .. note::
    Version 1.5 introduces a few changes that will require you to make a few minor modifications to
@@ -71,10 +67,10 @@ for your operating system for further details.
    :caption: Introduction
 
    int_introduction
-   int_started
    setup_linux
    setup_mac
    setup_windows
+   setup_other
 
 
 .. toctree::