Update README.md (css theming)

Author: MichaelDoyle

README.md

@@ -52,24 +52,24 @@ the desired behavior.
 
 Theming can be done with CSS variables
 
-- `--ngx-json-string` : color of string values
-- `--ngx-json-number` : color of number values
-- `--ngx-json-boolean` : color of boolean values
-- `--ngx-json-date` : color of date values
-- `--ngx-json-array` : color of array values
-- `--ngx-json-object` : color of object values
-- `--ngx-json-function` : color of function values
-- `--ngx-json-null` : color of null values
-- `--ngx-json-null-bg` : background color of null values
-- `--ngx-json-undefined` : color of undefined values
-- `--ngx-json-toggler` : color of toggler
-- `--ngx-json-key` : color of keys
-- `--ngx-json-punctuation : color of punctuation (`:`, `{`, `}`, etc)
-- `--ngx-json-value` : color of values
-- `--ngx-json-undefined-key` : color for key of undefined values
-- `--ngx-json-label` color of preview labels
-- `--ngx-json-font-family` : font-family
-- `--ngx-json-font-size` : font-size
+```css
+--ngx-json-string        /* color of string values */
+--ngx-json-number        /* color of number values */
+--ngx-json-boolean       /* color of boolean values */
+--ngx-json-date          /* color of date values */
+--ngx-json-function      /* color of function values */
+--ngx-json-null          /* color of null values */
+--ngx-json-null-bg       /* background color of null values */
+--ngx-json-undefined     /* color of undefined values */
+--ngx-json-toggler       /* color of toggler */
+--ngx-json-key           /* color of keys */
+--ngx-json-punctuation   /* color of punctuation (':', '{', '}', etc) */
+--ngx-json-value         /* color of values */
+--ngx-json-undefined-key /* color for key of undefined values */
+--ngx-json-label         /* color of preview labels */
+--ngx-json-font-family   /* font-family */
+--ngx-json-font-size     /* font-size */
+```
 
 ## Thanks