doc,timers: use code markup/markdown in headers

Backport-PR-URL: #31108
PR-URL: #31086
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Ruben Bridgewater <[email protected]>

Author: Trott

doc/api/timers.md

@@ -12,7 +12,7 @@ The timer functions within Node.js implement a similar API as the timers API
 provided by Web Browsers but use a different internal implementation that is
 built around the Node.js [Event Loop][].
 
-## Class: Immediate
+## Class: `Immediate`
 
 This object is created internally and is returned from [`setImmediate()`][]. It
 can be passed to [`clearImmediate()`][] in order to cancel the scheduled
@@ -23,7 +23,7 @@ running as long as the immediate is active. The `Immediate` object returned by
 [`setImmediate()`][] exports both `immediate.ref()` and `immediate.unref()`
 functions that can be used to control this default behavior.
 
-### immediate.hasRef()
+### `immediate.hasRef()`
 <!-- YAML
 added: v11.0.0
 -->
@@ -32,7 +32,7 @@ added: v11.0.0
 
 If true, the `Immediate` object will keep the Node.js event loop active.
 
-### immediate.ref()
+### `immediate.ref()`
 <!-- YAML
 added: v9.7.0
 -->
@@ -46,7 +46,7 @@ effect.
 By default, all `Immediate` objects are "ref'ed", making it normally unnecessary
 to call `immediate.ref()` unless `immediate.unref()` had been called previously.
 
-### immediate.unref()
+### `immediate.unref()`
 <!-- YAML
 added: v9.7.0
 -->
@@ -58,7 +58,7 @@ loop to remain active. If there is no other activity keeping the event loop
 running, the process may exit before the `Immediate` object's callback is
 invoked. Calling `immediate.unref()` multiple times will have no effect.
 
-## Class: Timeout
+## Class: `Timeout`
 
 This object is created internally and is returned from [`setTimeout()`][] and
 [`setInterval()`][]. It can be passed to either [`clearTimeout()`][] or
@@ -70,7 +70,7 @@ timer is active. Each of the `Timeout` objects returned by these functions
 export both `timeout.ref()` and `timeout.unref()` functions that can be used to
 control this default behavior.
 
-### timeout.hasRef()
+### `timeout.hasRef()`
 <!-- YAML
 added: v11.0.0
 -->
@@ -79,7 +79,7 @@ added: v11.0.0
 
 If true, the `Timeout` object will keep the Node.js event loop active.
 
-### timeout.ref()
+### `timeout.ref()`
 <!-- YAML
 added: v0.9.1
 -->
@@ -92,7 +92,7 @@ When called, requests that the Node.js event loop *not* exit so long as the
 By default, all `Timeout` objects are "ref'ed", making it normally unnecessary
 to call `timeout.ref()` unless `timeout.unref()` had been called previously.
 
-### timeout.refresh()
+### `timeout.refresh()`
 <!-- YAML
 added: v10.2.0
 -->
@@ -107,7 +107,7 @@ JavaScript object.
 Using this on a timer that has already called its callback will reactivate the
 timer.
 
-### timeout.unref()
+### `timeout.unref()`
 <!-- YAML
 added: v0.9.1
 -->
@@ -130,7 +130,7 @@ a certain period of time. When a timer's function is called varies depending on
 which method was used to create the timer and what other work the Node.js
 event loop is doing.
 
-### setImmediate(callback\[, ...args\])
+### `setImmediate(callback[, ...args])`
 <!-- YAML
 added: v0.9.1
 -->
@@ -172,7 +172,7 @@ async function timerExample() {
 timerExample();
 ```
 
-### setInterval(callback, delay\[, ...args\])
+### `setInterval(callback, delay[, ...args])`
 <!-- YAML
 added: v0.0.1
 -->
@@ -190,7 +190,7 @@ set to `1`. Non-integer delays are truncated to an integer.
 
 If `callback` is not a function, a [`TypeError`][] will be thrown.
 
-### setTimeout(callback, delay\[, ...args\])
+### `setTimeout(callback, delay[, ...args])`
 <!-- YAML
 added: v0.0.1
 -->
@@ -235,7 +235,7 @@ cancel the timer and prevent it from triggering.
 It is not possible to cancel timers that were created using the promisified
 variants of [`setImmediate()`][], [`setTimeout()`][].
 
-### clearImmediate(immediate)
+### `clearImmediate(immediate)`
 <!-- YAML
 added: v0.9.1
 -->
@@ -245,7 +245,7 @@ added: v0.9.1
 
 Cancels an `Immediate` object created by [`setImmediate()`][].
 
-### clearInterval(timeout)
+### `clearInterval(timeout)`
 <!-- YAML
 added: v0.0.1
 -->
@@ -254,7 +254,7 @@ added: v0.0.1
 
 Cancels a `Timeout` object created by [`setInterval()`][].
 
-### clearTimeout(timeout)
+### `clearTimeout(timeout)`
 <!-- YAML
 added: v0.0.1
 -->