[Design] Update / improve the Corporate Tiers PDF download

This was designed very quickly to meet a need and therefore it's visually very basic. We need to update it but I'd also like to give it a bit of a glow up in the process.

I'd also like us to include information about becoming a partner and the perks that attracts - read more here: https://mautic.org/become-a-mautic-partner/.

We need to add some more details and take some off:

• We don't sell tickets for the awards dinner any more
• Members now get a page on the members directory at all levels - see https://mautic.org/members-partners
• Members can specify up to five verticals they have clients in, and also specify the services they offer - which means they'll be featured on those landing pages in the members/partners section
• If they are a Mautic partner they get a lead capture form on their members directory pages

Here's the canva file: https://www.canva.com/design/DAFhNZ6NFsA/-gyGW_4FGC58EqFYkKGsDQ/edit (you need to be in our team to access - ping if you would like adding).

Open the linked Canva design and review the current Corporate Tiers PDF alongside the partner and members/partners pages. Update the visual presentation and the listed membership and partner benefits, remove the awards-dinner ticket detail, and export the revised PDF when all requested information is represented.