[website] Suppress warnings on yarn start

Summary:
This diff suppresses the warnings on yarn start.

```
~/infer/website$ yarn start
yarn run v1.22.22
$ docusaurus start
[INFO] Starting the development server...
[WARNING] Some blog authors used in "2015-05-22-Infer-on-open-source-android-apps.md" are not defined in "authors.yml":
- {"name":"Dulma Churchill","key":null,"page":null}

Note that we recommend to declare authors once in a "authors.yml" file and reference them by key in blog posts front matter to avoid author info duplication.
But if you want to allow inline blog authors, you can disable this message by setting onInlineAuthors: 'ignore' in your blog plugin options.
More info at https://docusaurus.io/docs/blog

[WARNING] Some blog authors used in "2016-08-30-curryon-rome-talk.md" are not defined in "authors.yml":
- {"name":"Peter O'Hearn","key":null,"page":null}

Note that we recommend to declare authors once in a "authors.yml" file and reference them by key in blog posts front matter to avoid author info duplication.
But if you want to allow inline blog authors, you can disable this message by setting onInlineAuthors: 'ignore' in your blog plugin options.
More info at https://docusaurus.io/docs/blog

[WARNING] Some blog authors used in "2016-03-17-collaboration-with-spotify.md" are not defined in "authors.yml":
- {"name":"Jules Villard","key":null,"page":null}

Note that we recommend to declare authors once in a "authors.yml" file and reference them by key in blog posts front matter to avoid author info duplication.
But if you want to allow inline blog authors, you can disable this message by setting onInlineAuthors: 'ignore' in your blog plugin options.
More info at https://docusaurus.io/docs/blog

[WARNING] Some blog authors used in "2016-11-28-atscale16.md" are not defined in "authors.yml":
- {"name":"Sam Blackshear","key":null,"page":null}

Note that we recommend to declare authors once in a "authors.yml" file and reference them by key in blog posts front matter to avoid author info duplication.
But if you want to allow inline blog authors, you can disable this message by setting onInlineAuthors: 'ignore' in your blog plugin options.
More info at https://docusaurus.io/docs/blog

[WARNING] Some blog authors used in "2016-06-23-first-opensourceversary.md" are not defined in "authors.yml":
- {"name":"Jules Villard","key":null,"page":null}

Note that we recommend to declare authors once in a "authors.yml" file and reference them by key in blog posts front matter to avoid author info duplication.
But if you want to allow inline blog authors, you can disable this message by setting onInlineAuthors: 'ignore' in your blog plugin options.
More info at https://docusaurus.io/docs/blog

[WARNING] Some blog authors used in "2016-04-07-mobileatscale-london-talk.md" are not defined in "authors.yml":
- {"name":"Dulma Churchill","key":null,"page":null}

Note that we recommend to declare authors once in a "authors.yml" file and reference them by key in blog posts front matter to avoid author info duplication.
But if you want to allow inline blog authors, you can disable this message by setting onInlineAuthors: 'ignore' in your blog plugin options.
More info at https://docusaurus.io/docs/blog

[WARNING] Some blog authors used in "2017-10-20-ocamlformat-released.md" are not defined in "authors.yml":
- {"name":"Josh Berdine","key":null,"page":null}

Note that we recommend to declare authors once in a "authors.yml" file and reference them by key in blog posts front matter to avoid author info duplication.
But if you want to allow inline blog authors, you can disable this message by setting onInlineAuthors: 'ignore' in your blog plugin options.
More info at https://docusaurus.io/docs/blog

[WARNING] Docusaurus found blog posts without truncation markers:
- "blog/2017-10-20-ocamlformat-released.md"
- "blog/2016-11-28-atscale16.md"
- "blog/2016-08-30-curryon-rome-talk.md"
- "blog/2016-06-23-first-opensourceversary.md"
- "blog/2016-04-07-mobileatscale-london-talk.md"
- "blog/2016-03-17-collaboration-with-spotify.md"
- "blog/2015-05-22-Infer-on-open-source-android-apps.md"

We recommend using truncation markers (`<!-- truncate -->` or `{/* truncate */}`) in blog posts to create shorter previews on blog paginated lists.
Tip: turn this security off with the `onUntruncatedBlogPosts: 'ignore'` blog plugin option.
[SUCCESS] Docusaurus website is running at: http://localhost:3000/

✔ Client
  Compiled successfully in 8.99s

client (webpack 5.95.0) compiled successfully
```

Reviewed By: ngorogiannis

Differential Revision:
D66365412

Privacy Context Container: L1208441

fbshipit-source-id: a01bc7a9335bace7b35847a3356c07cd72821326

website/docusaurus.config.js

@@ -110,6 +110,10 @@ module.exports = {
     [
       "@docusaurus/preset-classic",
       {
+        blog: {
+          onInlineAuthors: 'ignore',
+          onUntruncatedBlogPosts: 'ignore',
+        },
         docs: { sidebarPath: require.resolve("./sidebars.js") },
         theme: { customCss: require.resolve("./src/css/custom.css") },
         gtag: {