Unification of the Community Donation and Foundation Donation pages

[philpax]

When you search for "Bevy engine donation" via your favourite search engine, you will see both Supporting Bevy Development and Donate. To me, it's not immediately clear how these are related, especially as the latter is linked at the top-right under "Donate".

The two potential solutions that come to mind are:

• Merge the two pages, with redirects
• Explicitly cross-link the pages and explain the relationship between them