docs: improved SEO of documentation (#3117)

* docs: added description to documentation pages

* docs: added more descriptions

* docs: finished improving meta description

* docs: added searchbox structured data

* docs: added breadcrumbs structured data

* docs: added how to structured data

* docs: improved 404 page

* docs: added how-to frontmatter option

www/docs/docusaurus.config.js

@@ -210,7 +210,7 @@ const config = {
             [require('@docusaurus/remark-plugin-npm2yarn'), {sync: true}],
           ],
           showLastUpdateTime: true,
-          breadcrumbs: false,
+          // breadcrumbs: false,
           async sidebarItemsGenerator({defaultSidebarItemsGenerator, ...args}) {
             const sidebarItems = await defaultSidebarItemsGenerator(args);
             return reverseSidebar(sidebarItems);