Review of documentation and core project docs

[lb-]

Need someone to do a review of the grammar and general wording of this project's docs.

• README.md
• SECURITY.md
• CONTRIBUTING.md
• CONTRIBUTORS.md
• CHANGELOG.md

Checklist

• Must be written in Markdown and named README.md
• Must be visible on PyPI and renders properly
• Must have badges linking to PyPI and license
• Should have a badge linking to online code coverage results
• Must link to the changelog
• Must mention what versions of Python, Django and Wagtail are supported
• Must include an installation guide. This could be an abridged version of what is in the docs, but it must link to the full guide in the docs if this is the case
• Must link to full documentation (or, for small packages, documentation included directly in the readme)
• Must mention where to report security issues (security@wagtail.io)

[lb-]

Reached out to core team to get someone to read these.

[lb-]

Going to close this now, a few others have had a read - the code coverage can be done if needed as a future work.