message: Update fill_missing.html
diff: @@ -33,14 +33,15 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  </tr>
  <tr bgcolor="lightgrey">
  <td bgcolor="maroon"> <font color="white">
  - enum class fill_policy : unsigned char {<BR>
  - &emsp;value = 1,<BR>
  - &emsp;fill_forward = 2,<BR>
  - &emsp;fill_backward = 3,<BR>
  - &emsp;linear_interpolate = 4, // Using the index as X coordinate<BR>
  - &emsp;linear_extrapolate = 5, // Using the index as X coordinate<BR>
  - &emsp;mid_point = 6, // Mid-point of x and y<BR>
  - };</font>
  + <PRE>
  +enum class fill_policy : unsigned char {
  + value = 1,
  + fill_forward = 2,
  + fill_backward = 3,
  + linear_interpolate = 4, // Using the index as X coordinate
  + linear_extrapolate = 5, // Using the index as X coordinate
  + mid_point = 6, // Mid-point of x and y
  +};</PRE></font>
  </td>
  <td width="65%">
  This policy determines how to fill missing values in the DataFrame<BR>
  