make-github-repo-private: Fix bulleted list Markdown rendering
make-github-repo-private: Fix bulleted list Markdown rendering

- Needed a blank line between the bullets and the main text.
- I also took the opportunity for some rewording.

alphagov/govuk-developer-docs,alphagov/govuk-developer-docs,alphagov/govuk-developer-docs,alphagov/govuk-developer-docs