Have you read the Contributing Guidelines on issues?

• I have read the Contributing Guidelines on issues.

Prerequisites

• I'm using the latest version of Docusaurus.
• I have tried the npm run clear or yarn clear command.
• I have tried rm -rf node_modules yarn.lock package-lock.json and re-installing packages.
• I have tried creating a repro with https://new.docusaurus.io.
• I have read the console error message carefully (if applicable).

Description

In any docusaurus application including the official docusaurus website (https://docusaurus.io/docs), there are two <nav> elements, that don’t have aria-label.

Reproducible demo

No response

Steps to reproduce

1. Go to https://docusaurus.io/docs
2. Open dev tools
3. Search for <nav> elements (there are 4 <nav> elements in total)
4. First and second <nav> elements don’t have aria-label

Expected behavior

All <nav> elements have aria-label so that assistive technologies like screen readers can identify unique navigation elements.

Actual behavior

Main navigation and sidebar navigation elements don’t have an aria-label.
Currently, this is causing accessibility issues: https://dequeuniversity.com/rules/axe/4.4/landmark-unique.

Your environment

• Docusaurus version used: 2.2.0

Self-service

• I'd be willing to fix this bug myself.