unified hoverlabel: fix description

Author: antoinerg

src/components/fx/layout_attributes.js

@@ -61,12 +61,12 @@ module.exports = {
         editType: 'modebar',
         description: [
             'Determines the mode of hover interactions.',
-            'If `closest`, a single hoverlabel will appear',
-            'for the closest point within the `hoverdistance`.',
-            'If `x` (or `y`), multiple hoverlabels will appear for multiple points',
-            'at the closest `x`- (or `y`-) coordinate within the `hoverdistance`,',
+            'If *closest*, a single hoverlabel will appear',
+            'for the *closest* point within the `hoverdistance`.',
+            'If *x* (or *y*), multiple hoverlabels will appear for multiple points',
+            'at the *closest* x- (or y-) coordinate within the `hoverdistance`,',
             'with the caveat that no more than one hoverlabel will appear per trace.',
-            'If `x unified` (or `y unified`), a single hoverlabel will appear',
+            'If *x unified* (or *y unified*), a single hoverlabel will appear',
             'multiple points at the closest x- (or y-) coordinate within the `hoverdistance`',
             'with the caveat that no more than one hoverlabel will appear per trace.',
             'In this mode, spikelines are enabled by default perpendicular to the specified axis.',