Add new example to docs

Author: mborland

doc/modules/ROOT/nav.adoc

@@ -2,6 +2,7 @@
 * xref:basics.adoc[]
 * xref:examples.adoc[]
 ** xref:examples.adoc#examples_construction[Basic Construction]
+** xref:examples.adoc#examples_basic_math[Basic Arithmetic]
 ** xref:examples.adoc#examples_promotion[Promotion and Mixed Decimal Arithmetic]
 ** xref:examples.adoc#examples_charconv[`<charconv>`]
 ** xref:examples.adoc#examples_generic_programming[Generic Programming]

doc/modules/ROOT/pages/examples.adoc

@@ -33,6 +33,27 @@ Can not construct from invalid string
 ....
 ====
 
+[#examples_basic_math]
+== Basic Arithmetic
+
+.This https://github.com/cppalliance/decimal/blob/develop/examples/basic_arithmetic.cpp[example] demonstrates the behavior and functionality of arithmetic using a single type
+====
+[source, c++]
+----
+include::example$basic_arithmetic.cpp[]
+----
+
+.Expected Output:
+....
+A: -5.123456891234567
+B: 3.123456891234567
+A + B: -2
+abs(A + B): 2
+sqrt(abs(A + B)): 1.414213562373095
+Wolfram Alpha sqrt(2): 1.414213562373095
+....
+====
+
 [#examples_promotion]
 == Promotion and Mixed Decimal Arithmetic