Clean up README, elaborate on usage and documentation

Author: LRitzdorf

pdfpc/README.md

@@ -1,12 +1,14 @@
 # pdfpc
 
-This packages allows to define additional meta data within
-the PDF file which can be interpreted by the pdf presenter
-console (pdfpc) program.
+This LaTeX package provides a convenient way to specify notes and to define
+certain meta properties of the presentation when used with [PDF Presenter
+Console (`pdfpc`)](https://pdfpc.github.io), a GPLv3+ licensed multi-monitor PDF
+presentation viewer application available on GitHub.
+
 
 ## Dependencies
 
-`pdfpc` depends on these packages:
+The `pdfpc` package depends on these other packages:
 [`kvoptions`](https://ctan.org/pkg/kvoptions),
 [`xstring`](https://ctan.org/pkg/xstring),
 [`iftex`](https://ctan.org/pkg/iftex),
@@ -16,8 +18,56 @@ When using LuaTeX, it additionally depends on these packages:
 [`stringenc`](https://ctan.org/pkg/stringenc),
 [`pdftexcmds`](https://ctan.org/pkg/pdftexcmds)
 
+
 ## Usage
 
-It's best to read the [`pdfpc`](https://github.com/pdfpc/pdfpc) documentation
-for `pdfpc` integration.
+The [PDF Presenter Console](https://pdfpc.github.io) program accepts a variety
+of configuration options when started from the command line. (See the *pdfpc(1)*
+manual page for details.)
+
+This package allows certain details, such as presentation duration, default
+slide transitions, and speaker notes, to be specified within the metadata of the
+PDF itself, instead of via the command line. These settings are parsed by the
+PDF Presenter Console when the presentation is loaded.
+
+These parameters can be specified as package options, and/or via the `\pdfpcsetup` command.
+
+The following is a simple LaTeX document demonstrating a few example features:
+
+```latex
+\documentclass{beamer}
+\usepackage[overridenote]{pdfpc}
+% "overridenote" must be specified as a package option
+\pdfpcsetup{
+    % Other settings can be package options, or can go here
+    duration=5,
+    lastminutes=2,
+}
+
+% The usual Beamer document setup
+\title{\texttt{pdfpc} Example Presentation}
+\author{LRitzdorf}
+\institute{GitHub}
+\date{\today}
+
+\begin{document}
+\maketitle
+
+\begin{frame}
+    Hello PDFPC World!
+    % Because of "overridenote", this uses the pdfpc note command
+    \note{This speaker note will be shown by `pdfpc`, but hidden for the audience.}
+    \pause
+    Notice that the timer starts counting down from 5 minutes, just as we specified in the preamble!
+\end{frame}
+
+\end{document}
+```
+
+
+## Documentation
 
+Complete
+[documentation](http://mirrors.ctan.org/macros/latex/contrib/pdfpc/pdfpc-doc.pdf)
+for the current version of `pdfpc` is availble on [its CTAN
+page](https://ctan.org/pkg/pdfpc).