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* README: Rewrite with more information.

README

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-This project aims to produce at least a POSIX compliant sh replacement
-or even implement GNU bash.  On top of that it also intends to make
-scheme available for interactive and scripting application.  The
-approach also intends to allow capturing the intermediate scheme
-representation of the "original" shell script to offer a migration
-path away from [ba]sh. On top of this GNU make could similarly be
-replaced, as make turns out to be fraught with limitations and
-complexities.  One of the features I personally desire is not be
-forced to keep doing what was done in the past, i.e. once an object
-file is produced, it does not have to be produced again as long as the
-original is kept around. The orignal must be replaced when any of its
-dependencies change (source, compiler options, linker, etc.)
+Gash --- Guile As SHell
+***********************
 
-I feel that the shell has been instrumental on my path to embracing
-functional programming, however now I mostly experience that the
-language itselfs folds on functional expression, pun intended.
+Gash is a POSIX-compatible shell written in Guile Scheme.  It provides
+both the shell interface, as well as a Guile library for parsing shell
+scripts.  Gash is designed to bootstrap Bash as part of the Guix
+bootstrap process.  We are planning to develop Gash into a
+general-purpose shell and tool for building interfaces between Scheme
+and the shell.
 
+It is still early days for Gash.  At the moment, Gash is extremely
+limited and extremely slow, so we cannot recommend using it as your
+shell.  It does its bootstrapping job, and the parser works well for
+POSIX-compatible scripts, but that's about it.
 
-* history flattened vs full, i.e. navigate interactively without
-  redundancy vs export as script
+Installing
+==========
+
+This package uses GNU Autotools for building and installing.  For
+details on how to configure, build, and install it, see the file named
+'INSTALLING'.
+
+If you have GNU Guix, you can skip all that and install the package
+by running:
+
+     guix package -f guix.scm
+
+Gash is designed to work with Guile versions as early as 2.0.9.
+
+Normally, you should build Gash using 'configure' and 'make'.
+However, it can be built with nothing but Guile.  There is an example
+of this in the file 'tests/bootstrap/bash-without-bash.scm'.
+
+Testing
+=======
+
+Gash includes a number of unit and integration tests that can be run
+using 'make check'.  If you are using Guile 2.0.9, you will have to
+make SRFI 64 available to run the unit tests.  To do this, you can
+copy 'module/srfi/srfi-64.scm' and the 'module/srfi/srfi-64' directory
+from a newer version of Guile into a directory named 'srfi' in the
+Gash source code directory.
+
+If you have GNU Guix, you can also run the following extra tests.
+
+The bootstrap test can be run using 'make check-bootstrap'.  It builds
+Gash using nothing but Guix's bootstrap Guile, then uses Gash to build
+Bash using Guix's bootstrap toolchain.  This test is designed to make
+sure that Gash is suitable for bootstrapping.
+
+The specification tests can be run using 'make check-spec'.  These
+tests get copied and adapted from Oil <https://www.oilshell.org/>, and
+then run against Gash.
+
+Copying
+=======
+
+Gash is free software released under the GNU GPLv3 (or later).  See
+'COPYING' for the full license.  Enjoy!