Add project format documentation and popup box (#855)

* Add documentation of the various project file formats
* Add an info box  for updating to project format 1.3
* Add information on how to access the documentation
* Add a note on file format and rename a few things
* Fix some typos

docs/source/index.rst

@@ -48,6 +48,11 @@ This package can be extracted anywhere on your computer, and a setup script can
 the necessary icons and file associations. See :ref:`a_started`, or one or 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
+   some of the headings in your project. It should be fairly quick and straightforward. Please see
+   the :ref:`a_prjfmt_1_3` section for more details.
+
 **Useful Links**
 
 * Website: https://novelwriter.io
@@ -78,6 +83,7 @@ for your operating system for further details.
    usage_format
    usage_shortcuts
    usage_typography
+   usage_projectformat
 
 
 .. toctree::

docs/source/usage_projectformat.rst

@@ -0,0 +1,92 @@
+.. _a_prjfmt:
+
+**********************
+Project Format Changes
+**********************
+
+Most of the changes to the file formats over the history of novelWriter have no impact on the
+user-side of things. The project files are generally updated automatically. However, some of the
+changes require minor actions from the user.
+
+The key changes in the formats are listed below, as well as the user actions required where
+applicable.
+
+
+.. _a_prjfmt_1_3:
+
+Format 1.3 Changes
+==================
+
+This project format vas introduces in novelWriter version 1.5.
+
+With this format, the number of document layouts was reduced from 8 to 2. The conversion of
+document layouts is performed automatically when the project is opened.
+
+Due to the reduction of layouts, some features that were previously controlled by these layouts
+will be lost. These features are instead now controlled by syntax codes, so to recover these
+features, some minor modification must be made to select documents by the user.
+
+The manual changes the user must make should be very few as they apply to document layouts that
+should be used only a few places in any given project. These are as follows:
+
+**Title Pages**
+
+* The formatting of the level one title on the title page must be changed from ``# Title Text`` to
+  ``#! Title Text`` in order to retain the previous functionality. See :ref:`a_fmt_head`.
+* Any text that was previously centred on the page must be manually centred using the new text
+  alignment feature. See :ref:`a_fmt_align`.
+
+**Unnumbered Chapters**
+
+* Since the specific layout for unnumbered chapters has been dropped, such chapters must all use
+  the ``##! Chapter Name`` formatting code instead of ``## Chapter Name``. This also includes
+  chapters marked by an asterisk: ``## *Chapter Name``, as this feature has also been dropped.
+  See :ref:`a_fmt_head`.
+
+**Plain Pages**
+
+* The layout named "Plain Page" has also been removed. The only feature of this layout was that it
+  ensured that the content always started on a fresh page. In the new format, fresh pages can be
+  set anywhere in the text with the ``[NEW PAGE]`` code. See :ref:`a_fmt_break`.
+
+
+.. _a_prjfmt_1_2:
+
+Format 1.2 Changes
+==================
+
+This project format was introduces in novelWriter version 0.10.
+
+With this format, the way auto-replace entries were stored in the main project XML file changed.
+Opening an old project automatically converts the storage format up to and including version 1.1.1.
+
+Format 1.2 projects can be opened without loss of information up until version 1.1.1, and if the
+auto-replace is not being used, can still be opened in novelWriter as of version |release|.
+
+
+.. _a_prjfmt_1_1:
+
+Format 1.1 Changes
+==================
+
+This project format was introduces in novelWriter version 0.7.
+
+With this format, the ``content`` folder was introduced in the project storage. Previously, all
+novelWriter documents were saved in a series of folders numbered from ``data_0`` to ``data_f``.
+
+It also reduces the number of meta data and cache files. These files are automatically deleted if
+an old project is opened. This was also when the Table of Contents file was introduced.
+
+Format 1.1 projects can be opened without loss of information up until version 1.1.1, and if the
+auto-replace is not being used, can still be opened in novelWriter as of version |release|.
+
+
+.. _a_prjfmt_1_0:
+
+Format 1.0 Changes
+==================
+
+This is the original file format and project structure. It was in use up to version 0.6.3.
+
+Format 1.0 projects can be opened without loss of information up until version 1.1.1, and if the
+auto-replace is not being used, can still be opened in novelWriter as of version |release|.