UI - Live filters preview - Make it sticky in the viewport so its easier to build nice filters

changedetectionio/static/styles/scss/parts/_preview_text_filter.scss

@@ -24,6 +24,7 @@ body.preview-text-enabled {
 
   #text-preview {
     position: sticky;
+    top: 20px;
     padding-top: 1rem;
     padding-bottom: 1rem;
     display: block !important;

changedetectionio/static/styles/styles.css

@@ -474,6 +474,7 @@ body.preview-text-enabled {
     display: none; }
   body.preview-text-enabled #text-preview {
     position: sticky;
+    top: 20px;
     padding-top: 1rem;
     padding-bottom: 1rem;
     display: block !important; }