stylesheet: remove background and border from code spans

The new style makes the code spans lighter and more integrated into
the text and also makes the code spans more readable and
less intrusive.

A synopsis class is added for the code spans that are synopsis.

Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>

Author: jnavila

assets/sass/application.scss

@@ -32,7 +32,7 @@ $baseurl: "{{ .Site.BaseURL }}{{ if (and (ne .Site.BaseURL "/") (ne .Site.BaseUR
 
 code {
   display: inline;
-  padding: 0 5px;
+  padding: 0 0;
 }
 
 pre {

assets/sass/man-pages.scss

@@ -51,15 +51,13 @@
       word-wrap: break-word;       /* Internet Explorer 5.5+ */
       white-space: pre;
       white-space: pre-wrap;       /* css-3 */
-      background-color: #e8e7dd;
 
       em {
         font-weight: bold;
         font-style: normal;
       }
 
       code {
-        background-color: #e8e7dd;
         margin-bottom: 0;
         border: none;
         padding-left: 0;

assets/sass/typography.scss

@@ -260,8 +260,13 @@ code {
   line-height: $fixed-width-line-height;
   font-variant-ligatures: none;
   color: var(--orange);
-  background-color: var(--main-bg);
-  border: solid 1px var(--pre-border);
+}
+
+p {
+    .synopsis {
+	@include border-radius(3px);
+	border: solid 1px var(--pre-border);
+    }
 }
 
 // Quotes