Clean up arc-green theme (#4443)

* Resolve some issues with Arc Green

* Fix editor styles

* zeebra stripes

* generate CSS file

public/less/themes/arc-green.less

@@ -4,7 +4,6 @@
      display: block;
      overflow-x: auto;
      padding: 0.5em;
-     background-color: #2b2b2b !important;
      color: #bababa;
 }
  .repository.file.list .non-diff-file-content .code-view .lines-num, .repository.file.list .non-diff-file-content .code-view .lines-code ol {
@@ -322,6 +321,9 @@
      background-color: #2a2e3a;
      border: 1px solid #404552;
 }
+ .markdown:not(code) table tr:nth-child(2n) {
+     background-color: #474d61;
+}
  .ui.dropdown .menu {
      background: #2c303a;
 }
@@ -749,3 +751,17 @@
      box-shadow: 0 0 0 1px #609926 inset!important;
      color: #609926!important;
 }
+ .editor-toolbar {
+     background-color: #404552;
+     a {
+          color: #87ab63 !important;
+     }
+}
+ .CodeMirror {
+     color: #9daccc;
+     background-color: #2b2b2b;
+     border-top: none;    
+}
+ .CodeMirror-gutters{
+     background-color: #2b2b2b;
+}