[WIP - do not merge] Content section for writing guidelines in EUI

[florent-leborgne]

This PR adds a Content section on the new EUI site.
It also reworks entirely the content that was previously found under eui.elastic.co/writing.

This is a WIP and we'll be working more on it in the coming days.

Content is not ready.

[szabosteve]

I've pushed some changes against the Voice section in style.mdx and the content of the adapt-tone.mdx file via 631d3a631d3a. Please let me know if you think something should be adjusted or changed back. Thanks!

[florent-leborgne]

I've pushed additional changes on punctuation and case, as well as minor changes to general style recommendations. Please have a look.

[florent-leborgne]

I ported some of the relevant content currently under EUI > Writing to our new file structure, adding content about being conversational, minimalism, use of adverbs, and a few more things. Please have a look.

[kibanamachine]

Preview staging links for this PR:

• Docs site: https://eui.elastic.co/pr_7710/
• Storybook: https://eui.elastic.co/pr_7710/storybook
• New docs site (in development): https://eui.elastic.co/pr_7710/new-docs/

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: 8f47121

History

• 💚 Build #2037 succeeded ff81173
• 💚 Build #2027 succeeded c5a37ee
• 💚 Build #2023 succeeded 367ede2
• 💚 Build #1990 succeeded f889928
• 💚 Build #1960 succeeded c631d3a
• 💚 Build #1824 succeeded d8b49d6

cc @florent-leborgne