* include/freetype/ftimage.h: Fix type and link.

include/freetype/ftimage.h

@@ -318,7 +318,7 @@ FT_BEGIN_HEADER
    *
    *     If bit~2 is set, bits 5-7 contain the drop-out mode (as defined in
    *     the OpenType specification; the value is the same as the argument to
-   *     the 'SCANMODE' instruction).
+   *     the 'SCANTYPE' instruction).
    *
    *     Bits 3 and~4 are reserved for internal purposes.
    *
@@ -434,8 +434,8 @@ FT_BEGIN_HEADER
    *   rasterizer; see the `tags` field in @FT_Outline.
    *
    *   Please refer to the description of the 'SCANTYPE' instruction in the
-   *   OpenType specification (in file `ttinst1.doc`) how simple drop-outs,
-   *   smart drop-outs, and stubs are defined.
+   *   [OpenType specification](https://learn.microsoft.com/en-us/typography/opentype/spec/tt_instructions#scantype)
+   *   how simple drop-outs, smart drop-outs, and stubs are defined.
    */
 #define FT_OUTLINE_NONE             0x0
 #define FT_OUTLINE_OWNER            0x1