Hi Thaguru, welcome to the forum.

The following code would go into the worksheet module that contains the data. (Right-click on that sheet tab and choose View Code. Paste this code into the empty code area. Close the VB Editor. Run the macro from the Developer toolbar.)
Sub insRow()
Dim i As Long
For i = 1 To Range("A" & Rows.Count).End(xlUp).Row
    If Cells(i, 1).Font.Bold = True Then
        Cells(i, 1).Offset(1, 0).EntireRow.Insert
        i = i + 1
    End If
Next i
End Sub
It assumes your list is in A1:Axx (the last used row in column A is calculated automatically).

Hope that helps!