swift-scheduling: change footnotes to exercism/note (#2544)

Author: ErikSchierboom

exercises/swift-scheduling/instructions.md

@@ -32,12 +32,19 @@ There are two variable delivery date description patterns:
 - `"<N>M"` (N-th month)
 - `"Q<N>"` (N-th quarter)
 
-| Description | Meeting start              | Delivery date                                               |
-| ----------- | -------------------------- | ----------------------------------------------------------- |
-| `"<N>M"`    | Before N-th month          | At 8:00 on the _first_ workday¹ of this year's N-th month   |
-| `"<N>M"`    | After or in N-th month     | At 8:00 on the _first_ workday¹ of next year's N-th month   |
-| `"Q<N>"`    | Before or in N-th quarter² | At 8:00 on the _last_ workday¹ of this year's N-th quarter² |
-| `"Q<N>"`    | After N-th quarter²        | At 8:00 on the _last_ workday¹ of next year's N-th quarter² |
-
-¹ A workday is a Monday, Tuesday, Wednesday, Thursday, or Friday.
-² A year has four quarters, each with three months: January/February/March, April/May/June, July/August/September, and October/November/December.
+| Description | Meeting start             | Delivery date                                             |
+| ----------- | ------------------------- | --------------------------------------------------------- |
+| `"<N>M"`    | Before N-th month         | At 8:00 on the _first_ workday of this year's N-th month  |
+| `"<N>M"`    | After or in N-th month    | At 8:00 on the _first_ workday of next year's N-th month  |
+| `"Q<N>"`    | Before or in N-th quarter | At 8:00 on the _last_ workday of this year's N-th quarter |
+| `"Q<N>"`    | After N-th quarter        | At 8:00 on the _last_ workday of next year's N-th quarter |
+
+~~~~exercism/note
+A workday is a Monday, Tuesday, Wednesday, Thursday, or Friday.
+
+A year has four quarters, each with three months:
+1. January/February/March
+2. April/May/June
+3. July/August/September
+4. October/November/December.
+~~~~