[DOCS] Adds child_attributes CSS role (#1786)

Author: lcawl

resources/web/style/child_attributes.pcss

@@ -0,0 +1,10 @@
+#guide .child_attributes {
+  
+  details > div {
+    border: 1px solid #A9A9A9;
+    border-radius: 10px;
+    background: #fbfbfb;
+    padding: 15px 10px 0;
+    margin: 10px 5px 20px;
+  }
+}

resources/web/styles.pcss

@@ -7,6 +7,7 @@
 @import './style/alternative_picker.pcss';
 @import './style/admonishment.pcss';
 @import './style/calloutlist.pcss';
+@import './style/child_attributes.pcss';
 @import './style/conum.pcss';
 @import './style/code.pcss';
 @import './style/console_widget.pcss';