feature/UIDS-290-table-edits-part-2-multiple-sticky-columns (#294)

* add support for multiple sticky columns (left and right sides)

* updates documentation

* stickyColumnOffsetX prop takes number (px)

* update maxWidth minWidth props to take in a number

* mdx edits

Author: jasonbasuil

scss/box_shadow.scss

@@ -5,7 +5,8 @@ $ux-box-shadow-light: 0 1px 1px $ux-navbar-shadow-color;
 
 $ux-box-shadow-card: 0 2px 4px rgba(0,0,0,0.1);
 
-$ux-box-shadow-table-sticky-column: 2px 0px 1px 0px rgba(0, 0, 0, 0.05);
+$ux-box-shadow-table-sticky-column-left: 2px 0px 1px 0px rgba(0, 0, 0, 0.05);
+$ux-box-shadow-table-sticky-column-right: -2px 0px 1px 0px rgba(0, 0, 0, 0.05);
 
 $ux-box-shadow-top: 0 -2px 5px $ux-navbar-shadow-color;
 $ux-box-shadow-top-light: 0 -1px 1px $ux-navbar-shadow-color;