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, 70 insertions, 0 deletions

diff --git a/docs/source/lang/cpp/modulo.rst b/docs/source/lang/cpp/modulo.rst
new file mode 100644
index 0000000..013d07e
--- /dev/null
+++ b/docs/source/lang/cpp/modulo.rst
@@ -0,0 +1,70 @@
+.. highlight:: cpp
+
+.. _lang-modulo:
+
+Modulo Operator (``%``)
+=======================
+
+Calculates the `remainder <http://en.wikipedia.org/wiki/Remainder>`_
+when one integer is divided by another. It is useful for keeping a
+variable within a particular range (e.g.  the size of an array).
+
+Syntax
+------
+
+::
+
+    dividend % divisor
+
+Parameters
+----------
+
+**dividend**: the number to be divided
+
+**divisor**: the number to divide by
+
+Returns
+-------
+
+The remainder of **dividend**\ /\ **divisor**\ .
+
+Examples
+--------
+
+::
+
+    int x;
+    x = 7 % 5;   // x now contains 2
+    x = 9 % 5;   // x now contains 4
+    x = 5 % 5;   // x now contains 0
+    x = 4 % 5;   // x now contains 4
+
+::
+
+    /* update one value in an array each time through a loop */
+
+    int values[10];
+    int i = 0;
+
+    void setup() {
+        // no setup necessary
+    }
+
+    void loop() {
+      values[i] = analogRead(0);
+      i = (i + 1) % 10;   // modulo operator makes sure i stays between 0 and 9
+    }
+
+Tip
+---
+
+The modulo operator does not work on floats.  For that, you can use
+the C standard library function `fmod()
+<http://sourceware.org/newlib/libm.html#fmod>`_.
+
+See Also
+--------
+
+-  :ref:`Arithmetic <lang-arithmetic>`
+
+.. include:: /arduino-cc-attribution.txt