Update IHR url on /initiatives subnav

[kristinashu]

Update the 'Internet Health Report' link in the subnav from https://internethealthreport.org/ to https://foundation.mozilla.org/internet-health-report/

[ragnarokatz]

@kristinashu Hello, I would like to work on this issue please.

[ragnarokatz]

there are two places in total that need to be updated to the latest url: one in initiatives_page.html, one in participate_page.html.

[kristinashu]

Hi @ragnarokatz, thank you for pointing out the additional link on /participate. That one is editable in the CMS so I have just updated it now. But if you can, please go ahead and update the one on /initiatives.

cc @alanmoo