[a11y] Issue 9: Missing level-one heading (Participation Page)

[NewJerseyStyle]

Description:

The participation page does not contain a level-one heading (<h1>). This heading is important for screen reader users to navigate directly to the main content of the page.

Steps to Reproduce:

1. Navigate to the participation page (e.g. https://pol.is/4cvkai2ctw)
2. Inspect the page's heading structure.

Expected Behavior:

A <h1> element should be present to indicate the main content of the page.

Actual Behavior:

A <h1> element is missing.

Component/Area: Participation page

Source: Auto evaluation

Affected Elements: h1

[thomassth]

Should be fixed with https://github.com/CivicTechTO/polis/pull/32