Fix table headers (#980)

Signed-off-by: Andrew Boyarshin <andrew.boyarshin@gmail.com>

public/css/index.css

   margin-bottom: 0;
 }
 .markdown:not(code) table {
-  display: block;
-  width: 100%;
+  width: auto;
   overflow: auto;
   word-break: normal;
   word-break: keep-all;

public/less/_markdown.less

 	}
 
 	table {
-		display:block;
-		width:100%;
+		width:auto;
 		overflow:auto;
 		word-break:normal;
 		word-break:keep-all;