use footnotes

Author: cometkim

text/0001-int.md

@@ -47,7 +47,7 @@ Let `min_value` be $-2^{31}$ and `max_value` be $2^{31}-1$
 
 The [`ToInt32`] behavior follows the definition in ECMA-262 as is. ReScript compiler uses `bitwiseOR(number, 0)` in action. This is what appears in the output as `number | 0`, which truncates all special numbers defined in IEEE-754.
 
-The `fromNumber` shouldn't be directly exposed to the users. Applying the [`ToInt32`] operation to special numeric values, such as `Infinity`, can lead to subtle bugs. See related issues [a](https://github.com/rescript-lang/rescript/issues/6038), [b](https://github.com/rescript-lang/rescript/issues/6736), [c](https://github.com/rescript-lang/rescript/issues/6737).
+The `fromNumber` shouldn't be directly exposed to the users. Applying the [`ToInt32`] operation to special numeric values, such as `Infinity`, can lead to subtle bugs[^1][^2][^3].
 
 Instead, public APIs should wrap it and perform bounds-checking, if necessary, either emit errors (explained further in the ["API Consideration"](#api-consideration) section below) or notify the user via compiler warning.
 
@@ -206,4 +206,7 @@ However, this will not happen in the near future. It won't occur until we are co
 
 Guaranteeing the use of int32 types may offer additional advantages in the future when targeting WebAssembly or alternative native backends.
 
+[^1]: https://github.com/rescript-lang/rescript/issues/6038
+[^2]: https://github.com/rescript-lang/rescript/issues/6736
+[^3]: https://github.com/rescript-lang/rescript/issues/6737
 [`ToInt32`]: https://262.ecma-international.org/#sec-toint32