add additional shared libraries (#137)

* This merge request gives the ability to add shared libaries without set LD_LIBRARY_PATH variable.

 1. Generate file in /etc/ld.so.conf.d/
 2. update /etc/ld.so.cache with ldconfig command

example pillars:

linux:
  system:
    enabled: True
    ld:
      libraries:
        java:
          - /usr/lib/jvm/jre-openjdk/lib/amd64/server
          - /opt/java/jre/lib/amd64/server

* fix format in README.rst for Shared Libraries

* Fix for #137 - change pillar libraries key to library
diff --git a/README.rst b/README.rst
index b90c0f5..1449ee1 100644
--- a/README.rst
+++ b/README.rst
@@ -420,6 +420,23 @@
         cpu:
           governor: performance
 
+
+Shared Libraries
+~~~~~~~~~~~~~~~~
+
+Set additional shared library to Linux system library path
+
+.. code-block:: yaml
+
+    linux:
+      system:
+        ld:
+          library:
+            java:
+              - /usr/lib/jvm/jre-openjdk/lib/amd64/server
+              - /opt/java/jre/lib/amd64/server
+    
+
 Certificates
 ~~~~~~~~~~~~