Add link from openssf.org to developers landing page

[david-a-wheeler]

On the main website https://openssf.org/ under "Resources" I recommend adding a category named "For Developers" that links to the https://best.openssf.org/developers page. That will give software developers a "landing page" that points to the OpenSSF resources that are ready and specifically created for them.

Also: As part of this, let's note the "Developer landing page" in the best practices WG as one of its products.

Generally for "releases" of materials we (as a WG) make a decision to release something, so I think the same process should be used for the landing page.

[david-a-wheeler]

The OpenSSF website tab "Technical Initiatives / For Developers" specifically links to this landing page. So I think this is complete.