Fixed markdown syntax (#19060)

One backtick was missing from the starting tag of a code block, which had downstream effects.

client/src/pages/guide/english/html/attributes/font-color-attribute/index.md

@@ -6,7 +6,7 @@ title: Font Color Attribute
 This attribute is used to set a color to the text enclosed in a ```<font>``` tag.
 
 ### Syntax:
- ``html
+ ```html
  <font color= "color">
  ```
  
@@ -40,4 +40,4 @@ A color can also be specified using a 'hex code' or an 'rgb code', instead of us
     <font color="rgb(0,255,0)">Font color example using color attribute</font>
   </body>
 </html>
-```
+```