doc-rst: customize RTD theme, drop padding of inline literal

Remove the distracting (left/right) padding of inline literals. (HTML
<code>). Requested and discussed in [1].

[1] http://www.spinics.net/lists/linux-media/msg103991.htmlSigned-off-by: NMarkus Heiser <markus.heiser@darmarIT.de>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Documentation/sphinx-static/theme_overrides.css

@@ -42,11 +42,12 @@
     caption a.headerlink { opacity: 0; }
     caption a.headerlink:hover { opacity: 1; }
 
-    /* inline literal: drop the borderbox and red color */
+    /* inline literal: drop the borderbox, padding and red color */
 
     code, .rst-content tt, .rst-content code {
         color: inherit;
         border: none;
+        padding: unset;
         background: inherit;
         font-size: 85%;
     }