doc: update link to V8 Embedder's guide

V8 moved the Embeder's guide to GitHub.

PR-URL: #11336
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

doc/api/addons.md

@@ -1110,7 +1110,7 @@ const addon = require('./build/Release/addon');
 
 [bindings]: https://github.com/TooTallNate/node-bindings
 [download]: https://github.com/nodejs/node-addon-examples
-[Embedder's Guide]: https://developers.google.com/v8/embed
+[Embedder's Guide]: https://github.com/v8/v8/wiki/Embedder's%20Guide
 [examples]: https://github.com/nodejs/nan/tree/master/examples/
 [installation instructions]: https://github.com/nodejs/node-gyp#installation
 [libuv]: https://github.com/libuv/libuv

doc/api/vm.md

@@ -469,6 +469,6 @@ associating it with the `sandbox` object is what this document refers to as
 [`vm.runInContext()`]: #vm_vm_runincontext_code_contextifiedsandbox_options
 [`vm.runInThisContext()`]: #vm_vm_runinthiscontext_code_options
 [`eval()`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/eval
-[V8 Embedder's Guide]: https://developers.google.com/v8/embed#contexts
+[V8 Embedder's Guide]: https://github.com/v8/v8/wiki/Embedder's%20Guide#contexts
 [contextified]: #vm_what_does_it_mean_to_contextify_an_object
 [command line option]: cli.html