doc: Fix misuse of $ instead of @ in comments

$ renders the next word monospaced whereas @ turns the next word into a link.

src/lib/elementary/efl_ui_widget.eo

@@ -165,8 +165,8 @@ abstract Efl.Ui.Widget (Efl.Canvas.Group, Efl.Access.Object,
 
            Note: This may not be a display manager window in case of nested
            canvases. If a "real" window is required, then you might want to
-           verify that the returned object is a $Efl.Ui.Win_Inlined, and then
-           get $Efl.Ui.Win_Inlined.inlined_parent to find an object in the
+           verify that the returned object is a @Efl.Ui.Win_Inlined, and then
+           get @Efl.Ui.Win_Inlined.inlined_parent to find an object in the
            master window.
 
            See also @.widget_parent.

src/lib/elementary/elm_prefs.eo

@@ -23,7 +23,7 @@ class Elm.Prefs (Efl.Ui.Widget, Efl.File, Efl.Ui.Legacy)
            widget.
 
            When $obj dies, the values of the elements declared on its
-           .epb file (the one set on elm_prefs_file_set()) marked as permanent
+           $.epb file (the one set on elm_prefs_file_set()) marked as permanent
            will be written back to prefs_data, if it is writable.
            One is also able to make this writing event to take place
            automatically after each UI element modification by using

src/lib/evas/canvas/evas_canvas.eo

@@ -697,7 +697,7 @@ class Evas.Canvas (Efl.Loop_Consumer, Efl.Canvas.Scene, Efl.Animator, Efl.Input.
          */
          return: list<ptr(Eina.Rect)> @owned @warn_unused; [[
             A newly allocated list of updated rectangles of the canvas
-            ($Eina.Rect structs). Free this list with
+            (@Eina.Rect structs). Free this list with
             \@ref evas_render_updates_free.
          ]]
       }