doc: fix quotes mistypes in inline code blocks

This fixes trivial invalid quotes mistypes in inline code blocks,
e.g. forgotten quotes or mixed order.

Whether this could be easily automatically checked in lint is a
separate question: e.g. `'` is valid.

PR-URL: #19713
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

Author: ChALkeR

doc/api/http2.md

@@ -439,7 +439,7 @@ payload.
 session.ping(Buffer.from('abcdefgh'), (err, duration, payload) => {
   if (!err) {
     console.log(`Ping acknowledged in ${duration} milliseconds`);
-    console.log(`With payload '${payload.toString()}`);
+    console.log(`With payload '${payload.toString()}'`);
   }
 });
 ```

doc/api/process.md

@@ -211,7 +211,7 @@ changes:
                  a process warning.
 -->
 
-The `'unhandledRejection`' event is emitted whenever a `Promise` is rejected and
+The `'unhandledRejection'` event is emitted whenever a `Promise` is rejected and
 no error handler is attached to the promise within a turn of the event loop.
 When programming with Promises, exceptions are encapsulated as "rejected
 promises". Rejections can be caught and handled using [`promise.catch()`][] and