[m-rev.] for review 3/3: Make a number of changes to the README.md file

[Paul Bone]

Branches: master

For review by anyone.

---

Make a number of changes to the README.md file

README.md:
    Reorder the list or README files to that they occur from most relevant
    to new users to least relevant.  In particular put commonly-used
    backends and platforms earlier in the list.

    Provide some introductory text that introduce the user to the multiple
    backends available.

    Add further links to more information such as the documentation.

    Add text so that the file reads more natrually.
---
 README.md | 80 ++++++++++++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 61 insertions(+), 19 deletions(-)

diff --git a/README.md b/README.md
index 3c89514..a9b6b90 100644
--- a/README.md
+++ b/README.md
@@ -1,43 +1,85 @@
 Mercury
 =======
 
-[Mercury](http://www.mercurylang.org/) is a logic/functional programming language which combines the clarity and the expressiveness of declarative programming with advanced static analysis and error detection features.
+[Mercury](http://www.mercurylang.org/) is a logic/functional programming
+language which combines the clarity and the expressiveness of declarative
+programming with advanced static analysis and error detection features.
+
+This README file contains very little information itself.  It is intended to
+direct the reader to the specific information they're looking for.
+More detailed information is available on the [website's about
+pages](http://www.mercurylang.org/about.html), in other README files in the
+root directory of the source code repository, and in the
+[documentation](http://www.mercurylang.org/documentation/documentation.html).
+
+## README files
+
+Mercury has a number of different
+[Backends](http://www.mercurylang.org/about/backends.html) These include two
+different C backends, plus backends for Java, C# and Erlang.
+Mercury also works on different operating systems and with different C
+compilers.  Specific information is contained in individual README files as
+follows:
+
+ * [Bootstrapping](README.bootstrap) discusses how to get Mercury installed.
+
+   This is important as Mercury is written in Mercury, so installing Mercury
+   without an existing installation of Mercury requires bootstrapping.
+
+ * C Low-level backend
+
+   This backend works well with GCC but also works with:
 
-## Instructions
- 
- * Low-level backend compilers
-  * [.Net IL](README.DotNet)
   * [Clang](README.clang)
   * [lcc](README.lcc)
+
  * High-level backend targets
+  * C
   * [C#](README.CSharp)
   * [Erlang](README.Erlang)
   * [Java](README.Java)
- * [Bootstrapping](README.bootstrap)
+ * Experimental / Obsolete backends
+  * [.Net IL](README.DotNet)
  * Unix
+  * [Linux](README.Linux)
+   * [Alpha](README.Linux-Alpha)
+   * [PPC](README.Linux-PPC)
+   * [m68k](README.Linux-m68k)
+  * [MacOS](README.MacOS)
   * [FreeBSD](README.FreeBSD)
   * [AIX](README.AIX)
   * [HP-UX](README.HPUX)
-  * [Solaris](README.Solaris)
   * [IRIX-5](README.IRIX-5)
-  * [MacOS](README.MacOS)
- * [Linux](README.Linux)
-  * [Alpha](README.Linux-Alpha)
-  * [PPC](README.Linux-PPC)
-  * [m68k](README.Linux-m68k)
- * Cross compilation
-  * [MinGW](README.MinGW-cross)
+  * [Solaris](README.Solaris)
  * [Windows](README.MS-Windows)
   * Using the [Visual C compiler](README.MS-VisualC)
   * Using the [MinGW gcc compiler](README.MinGW)
   * Using the [Cygwin](README.Cygwin) environment
+ * Cross compilation
+  * [MinGW](README.MinGW-cross)
+
+## Other information
 
-## Notes
+Other information is available in text files in the source code repository.
 
 See the current [release notes](RELEASE_NOTES) for the latest stable release.
-Please the the [history](HISTORY) if you want to find out more about the past development,
-and the [news](NEWS) for any current or future enhancements.
+The [history](HISTORY) file is relevant if you want to find out more about the
+past development of Mercury.
+[News](NEWS) lists any current or future enhancements (but this isn't
+always up-to-date).
+The [limitations](LIMITATIONS) file lists a number of ways in which the
+Mercury implementation does not yet meet its goals.
+
+## Information for developers
+
+If you are considering contributing to the Mercury project the website
+contains that may be helpful.  These include a document about
+[contributions in general](http://www.mercurylang.org/development/contributions.html) and
+[specific information](http://www.mercurylang.org/development/developer.html)
+about contributing such as coding styles.
+
+## Contact
 
-## Limitations
+Finally contact information is provided on [our contact
+page](http://www.mercurylang.org/contact.html).
 
-Currently, the following [limitations](LIMITATIONS) exist in the implementation.
-- 
2.0.0.rc0