Docusaurus 2.2

We are happy to announce Docusaurus 2.2.

The upgrade should be easy: as explained in our release process documentation, minor versions respect Semantic Versioning.

Highlights

Mermaid diagrams

In #7490, we added support for Mermaid diagrams. This fills the gap between GitHub Flavored Markdown which also added support recently. You can create Mermaid diagrams using Markdown code blocks:

```mermaid
sequenceDiagram
    participant Alice
    participant Bob
    Alice->>John: Hello John, how are you?
    loop Health check
        John->>John: Fight against hypochondria
    end
    Note right of John: Rational thoughts 
prevail!
    John-->>Alice: Great!
    John->>Bob: How about you?
    Bob-->>John: Jolly good!
```

mdx-code-block

import BrowserWindow from '@site/src/components/BrowserWindow';

<BrowserWindow>

```mermaid
sequenceDiagram
    participant Alice
    participant Bob
    Alice->>John: Hello John, how are you?
    loop Health check
        John->>John: Fight against hypochondria
    end
    Note right of John: Rational thoughts 
prevail!
    John-->>Alice: Great!
    John->>Bob: How about you?
    Bob-->>John: Jolly good!
```

</BrowserWindow>

Make sure to check the documentation, and the more advanced examples

Config `headTags`

In #8151, we added the ability to apply arbitrary HTML <head> tags to all pages of your site.

module.exports = {
  headTags: [
    {
      tagName: 'link',
      attributes: {
        rel: 'icon',
        href: '/img/docusaurus.png',
      },
    },
  ],
};

Accessibility

We did several accessibility improvements:

#8207: improves keyboard navigation for mobile drawer hamburger button
#8161: improves keyboard navigation for tabs
#8204: makes the skip to content button support progressive enhancement
#8174: improves screen reader announcement when toggling between light/dark mode

Developer Experience

We made validation stricter and improved error messages:

#8234: in case of doc processing failure, prints the problematic markdown file path in the error message
#8192 and #8159: validates siteConfig.url more strictly and with better error message
#8066: makes config url and baseUrl fail-safe and less sensitive to the presence or absence of a leading or trailing slash

Translations

We completed the default theme translation support for multiple languages:

🇹🇷 #8105: completes Turkish translations
🇷🇺 #8253: completes Russian translations
🇫🇷 #8243: completes French translations
🇯🇵 #8075: completes Japanese translations

:::tip

Completing theme translations is an ongoing effort and an easy way to contribute to Docusaurus. We add new theme features regularly, for which we often need new translations.

:::

Other changes

Other notable changes include:

#8210: the docusaurus swizzle CLI has a new --config option
#8109: mobile navigation performance optimizations, prefetch resources earlier
#8059: versions/locales navbar dropdowns preserve hash and querystring on navigation
#8227: the client redirect plugin preserves hash and querystring on redirect

Check the 2.2.0 changelog entry for an exhaustive list of changes.