doc: add CSS support for hlist directive

Lists that are long and narrow can be displayed better using the
hlist directive:

.. hlist::
   :columns: 3

   * item 1
   * item 2
   * item 3
   * item 4
   * item 5
   * item 6
   * item 7
   * item 8
   * item 9
   * item 10

Will display as:

   * item 1  * item 5  * item 8
   * item 2  * item 6  * item 9
   * item 3  * item 7  * item 10
   * item 4

and with this patch, the generated table will display full page width
instead of compact.

Change-Id: I238a22461c45b51911d2d3039c9e5eb0c4dbf23c
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>

doc/conf.py

@@ -168,7 +168,7 @@ html_add_permalinks = ""
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = []
+html_static_path = ['static']
 
 # Add any extra paths that contain custom files (such as robots.txt or
 # .htaccess) here, relative to this directory. These files are copied
@@ -328,3 +328,6 @@ html_context = {
 }
 
 extlinks = {'jira': ('https://jira.zephyrproject.org/browse/%s', '')}
+
+def setup(app):
+   app.add_stylesheet("zephyr-custom.css")

doc/static/zephyr-custom.css

@@ -0,0 +1,6 @@
+/* -- Extra CSS styles for Zephyr content ----------------------------------- */
+
+/*  make .. hlist:: tables fill the page */
+table.hlist {
+    width: 95% !important;
+}