docs: Convert 'docs' index page to rst

Along with the conversion we need to adapt the stylesheets to apply to
the new document similarly to how we do that in the knowledge base.

Note that one visible difference is that now a 'Documentation' heading
is visible on top of the page.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

docs/css/libvirt.css

@@ -105,8 +105,8 @@
 }
 
 #index.document,
-#docs.document,
 #hvsupport.document,
+#documentation.document,
 #knowledge-base.document
 {
     width: inherit;
@@ -397,6 +397,7 @@ h6:hover > a.headerlink {
 }
 
 div.panel,
+#documentation .section,
 #knowledge-base .section
 {
     width: 24%;
@@ -406,6 +407,7 @@ div.panel,
 }
 
 div.panel h2,
+#documentation .section h1,
 #knowledge-base .section h1 {
     margin-top: 0px;
     padding: 0.5em;
@@ -423,15 +425,12 @@ div.panel h2,
     height: 300px;
 }
 
+#documentation.document > h1,
 #knowledge-base.document > h1 {
     text-align: center;
     padding: 1em;
 }
 
-#docs.document h1 {
-    visibility: hidden;
-}
-
 br.clear {
     clear: both;
     border: 0px;
@@ -485,11 +484,13 @@ br.clear {
 }
 
 div.panel dd,
+#documentation dd,
 #knowledge-base dd {
     font-size: smaller;
 }
 
 div.panel a,
+#documentation a,
 #knowledge-base a {
     text-decoration: none;
 }
@@ -497,6 +498,9 @@ div.panel a,
 div.panel ul,
 div.panel p,
 div.panel dl,
+#documentation ul,
+#documentation p,
+#documentation dl,
 #knowledge-base ul,
 #knowledge-base p,
 #knowledge-base dl {
@@ -505,16 +509,19 @@ div.panel dl,
 }
 
 div.panel ul,
+#documentation ul,
 #knowledge-base ul {
     margin-left: 1em;
 }
 
 div.panel dt,
+#documentation dt,
 #knowledge-base dt {
     margin: 0px;
 }
 
 div.panel dd,
+#documentation dd,
 #knowledge-base dd {
     margin: 0px;
     margin-bottom: 1em;