manual: replace old README

Signed-off-by: Gerwin Klein <gerwin.klein@proofcraft.systems>

manual/README

@@ -1,31 +0,0 @@
-<!--
-     Copyright 2014, General Dynamics C4 Systems
-
-     SPDX-License-Identifier: GPL-2.0-only
--->
-
-seL4 manual (including API). Default make target builds a PDF.
-
-Original text from paper template README follows...
-$Id: README,v 1.6 2007-03-07 15:09:26 gernot Exp $
-
-A note on referencing:
-
-The paper/report template can now handle the use of bibexport, and is set up to
-use this method by default. In your paper or report, instead of specifying your
-bibfile sources in the \bibliography{file0,file1} command, you simply specify
-\bibliography{references}. Specify your source bibfiles in the Makefile as
-described above.
-
-At make time, the build system will parse your targets for citations and then
-collate all the BibTeX entries in references.bib.
-This is useful for several reasons. If you need to hand edit BibTeX entries to
-save room in your paper, you don't need to edit the ERTOS bibfiles, or make
-duplicates on entries in extras.bib. It also means that BibTeX entries are stored
-with the paper in the repository.
-
-The Makefile is smart. If you add or remove a reference to a target, the build
-system will ask you whether you want to rebuild references.bib. This is to ensure
-that if you have made changes by hand to any references, these aren't overwritten.
-
-Consider updating this template when appropriate.

manual/README.md

@@ -0,0 +1,17 @@
+<!--
+     Copyright 2021, seL4 Project a Series of LF Projects, LLC
+
+     SPDX-License-Identifier: CC-BY-SA-4.0
+-->
+
+seL4 Reference Manual
+=====================
+
+To build a PDF use
+
+    make
+
+You will need recent version of `LaTeX` and `doxygen`.
+
+The main source file is `manual.tex`, most of the text is in `parts/`,
+and most of the API reference is generated with `doxygen`.