doc: format v8.md in preparation for stricter linting

PR-URL: #40647
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>

Author: Trott

doc/api/v8.md

@@ -625,6 +625,7 @@ stopHookSet();
 ```
 
 ### `promiseHooks.onInit(init)`
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@@ -648,6 +649,7 @@ const stop = promiseHooks.onInit((promise, parent) => {});
 ```
 
 ### `promiseHooks.onSettled(settled)`
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@@ -672,6 +674,7 @@ const stop = promiseHooks.onSettled((promise) => {});
 ```
 
 ### `promiseHooks.onBefore(before)`
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@@ -696,6 +699,7 @@ const stop = promiseHooks.onBefore((promise) => {});
 ```
 
 ### `promiseHooks.onAfter(after)`
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@@ -720,6 +724,7 @@ const stop = promiseHooks.onAfter((promise) => {});
 ```
 
 ### `promiseHooks.createHook(callbacks)`
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@@ -776,7 +781,7 @@ not necessarily ever even be garbage collected.
 
 Because promises are asynchronous resources whose lifecycle is tracked
 via the promise hooks mechanism, the `init()`, `before()`, `after()`, and
-`settled()` callbacks *must not* be async functions as they create more
+`settled()` callbacks _must not_ be async functions as they create more
 promises which would produce an infinite loop.
 
 While this API is used to feed promise events into [`async_hooks`][], the