Add examples for API documentation of MatrixBase::cwiseXxx() methods.
diff --git a/doc/snippets/MatrixBase_cwiseSqrt.cpp b/doc/snippets/MatrixBase_cwiseSqrt.cpp
new file mode 100644
index 0000000..4bfd75d
--- /dev/null
+++ b/doc/snippets/MatrixBase_cwiseSqrt.cpp
@@ -0,0 +1,2 @@
+Vector3d v(1,2,4);
+cout << v.cwiseSqrt() << endl;