Translate UI strings to Italian

[clairefro]

In preparation for publishing tutorial pt1 in Italian, we need to translate the Navbar and Footer strings.

To do this, use the Spanish UI string translation as a guide.

1. From project root, cp -r i18n/es/docusaurus-theme-classic i18n/it/docusaurus-theme-classic
2. In i18n/it/docusaurus-theme-classic, for each string in footer.json and navbar.json, translate the message property value

Please preserve proper nouns like "Discord", "Discourse", "GitHub" etc. as-is.

That's it! Docusaurus is set up to look for i18n strings at this filepath, so once these json files are translated these strings will be automatically resolved for any /it page