Add content changes to support HeroDevs partnership.

[AndreAngelantoni]

Sister to https://github.com/jquery/jquery-wp-content/issues/462 (Add HeroDevs support messaging for jQuery). See that issue for more details.

This issue is to update the wording of the main page and the support page. On the support page, add a new Support section and move paragraphs around, per the definition document.