readd .markdown class to all markup renderers (#8357)

fixes #8299, a regression from 867f46f.
unlike it's name suggests, the .markdown class is needed for most markup types.
a future refactor should rename this class to something more generic

public/css/index.css

@@ -505,7 +505,7 @@ footer .ui.left,footer .ui.right{line-height:40px}
 .repository.file.list .non-diff-file-content .view-raw img{padding:5px 5px 0 5px}
 .repository.file.list .non-diff-file-content .plain-text{padding:1em 2em 1em 2em}
 .repository.file.list .non-diff-file-content .plain-text pre{word-break:break-word;white-space:pre-wrap}
-.repository.file.list .non-diff-file-content .csv{overflow-x:auto}
+.repository.file.list .non-diff-file-content .csv{overflow-x:auto;padding:0!important}
 .repository.file.list .non-diff-file-content pre{overflow:auto}
 .repository.file.list .sidebar{padding-left:0}
 .repository.file.list .sidebar .octicon{width:16px}

public/less/_repository.less

@@ -429,6 +429,7 @@
 
             .csv {
                 overflow-x: auto;
+                padding: 0 !important;
             }
 
             pre {

templates/repo/view_file.tmpl

@@ -45,7 +45,7 @@
 		</div>
 	</h4>
 	<div class="ui attached table unstackable segment">
-		<div class="file-view {{if .IsMarkup}}{{.MarkupType}}{{else if .IsRenderedHTML}}plain-text{{else if .IsTextFile}}code-view{{end}} has-emoji">
+		<div class="file-view {{if .IsMarkup}}{{.MarkupType}} markdown{{else if .IsRenderedHTML}}plain-text{{else if .IsTextFile}}code-view{{end}} has-emoji">
 			{{if .IsMarkup}}
 				{{if .FileContent}}{{.FileContent | Safe}}{{end}}
 			{{else if .IsRenderedHTML}}