doc: add missing <code> blocks

PR-URL: #58995
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Juan José Arboleda <[email protected]>

Author: aduh95

doc/api/assert.md

@@ -129,7 +129,7 @@ Legacy assertion mode may have surprising results, especially when using
 assert.deepEqual(/a/gi, new Date());
 ```
 
-## Class: assert.AssertionError
+## Class: `assert.AssertionError`
 
 * Extends: {errors.Error}
 

test/common/README.md

@@ -841,7 +841,7 @@ frames for testing of HTTP/2 endpoints
 const http2 = require('../common/http2');
 ```
 
-### Class: Frame
+### Class: `Frame`
 
 The `http2.Frame` is a base class that creates a `Buffer` containing a
 serialized HTTP/2 frame header.
@@ -861,7 +861,7 @@ socket.write(frame.data);
 
 The serialized `Buffer` may be retrieved using the `frame.data` property.
 
-### Class: HeadersFrame
+### Class: `HeadersFrame`
 
 The `http2.HeadersFrame` is a subclass of `http2.Frame` that serializes a
 `HEADERS` frame.
@@ -880,7 +880,7 @@ const frame = new http2.HeadersFrame(id, payload, padlen, final);
 socket.write(frame.data);
 ```
 
-### Class: SettingsFrame
+### Class: `SettingsFrame`
 
 The `http2.SettingsFrame` is a subclass of `http2.Frame` that serializes an
 empty `SETTINGS` frame.
@@ -1138,7 +1138,7 @@ See the source code for definitions. Please avoid using it in new
 code - the current usage of this port in tests is being migrated to
 the original WPT harness, see [the WPT tests README][].
 
-### Class: WPTRunner
+### Class: `WPTRunner`
 
 A driver class for running WPT with the WPT harness in a worker thread.