Document \. for regex function (hashicorp#37014)

Author: radeksimko

website/docs/language/functions/regex.mdx

@@ -86,7 +86,7 @@ of the pattern must be escaped as `\\`.
 | `(x)`                  | unnamed capture group for sub-pattern `x`                                        |
 | `(?P<name>x)`          | named capture group, named `name`, for sub-pattern `x`                           |
 | `(?:x)`                | non-capturing sub-pattern `x`                                                    |
-| `\*`                   | Literal `*` for any punctuation character `*`                                    |
+| `\*`                   | Literal `*` for any punctuation character `*` For example, `\.` is a literal `.` |
 | `\Q...\E`              | Literal `...` for any text `...` as long as it does not include literally `\E`   |
 
 In addition to the above matching operators that consume the characters they