merge libmaple docs ("leaflabs-docs") into ./docs

In the past, libample documentation was forked out of this repository
because the documentation had increased in scope. For the librambutan,
and the rambutan project in general, we will try to keep documentation
closer to the source code, so the librambutan-specific documentation
should live here. Other sections of leaflabs-docs will be culled in a
following commit.

This merge attempts to maintain history by using a subtree strategy.
Followed directions at:

    http://nuclearsquid.com/writings/subtree-merging-and-you/

Full history for files should be accessible using the "--follow" flag to
git log, eg:

    git log --follow docs/source/adc.rst

It should be possible to pull patches from leaflabs-docs with:

    git pull -s subtree leaflabs-docs master

... at least until the docs in this repository diverge significantly.

1 files changed, 50 insertions, 0 deletions

diff --git a/docs/source/language-index.rst b/docs/source/language-index.rst
new file mode 100644
index 0000000..5e4c609
--- /dev/null
+++ b/docs/source/language-index.rst
@@ -0,0 +1,50 @@
+.. _language-index:
+
+=======================
+Complete Language Index
+=======================
+
+This is the index of Maple's :ref:`language reference
+<language-lang-docs>` documentation.  The "Maple API" column provides
+API references for documented libmaple functionality. The "C++ for
+Maple" pages are intended as a minimal reference/refresher for
+programmers familiar with the Arduino language.
+
+.. admonition:: **Looking for Something Else?**
+
+   - See the :ref:`libraries` for extra built-in libraries for dealing
+     with different kinds of hardware.
+
+   - If you're looking for something from the C standard library (like
+     ``atoi()``, for instance), see :ref:`this FAQ <faq-atoi>`.
+
+   - If you're looking for pointers to low-level details, see the
+     :ref:`Language Recommended Reading
+     <language-recommended-reading>` and :ref:`libmaple` pages.
+
+.. _index-language-index-cpp:
+.. _index-language-index-api:
+
++----------------------------------+------------------------------------+
+|   Maple API                      |   C++ for Maple                    |
+|                                  |                                    |
++==================================+====================================+
+|                                  |                                    |
+|  .. toctree::                    |  .. toctree::                      |
+|     :maxdepth: 1                 |     :maxdepth: 1                   |
+|     :glob:                       |     :glob:                         |
+|                                  |                                    |
+|     lang/api/*                   |     lang/cpp/*                     |
+|                                  |                                    |
++----------------------------------+------------------------------------+
+
+.. Unimplemented or not part of current release:
+
+.. toctree::
+   :hidden:
+
+   lang/unimplemented/tone.rst
+   lang/unimplemented/notone.rst
+   lang/unimplemented/pulsein.rst
+   lang/unimplemented/stringclass.rst
+   lang/unimplemented/stringobject.rst