Update membership workflow

[shanda-eclipse]

We need to update the membership workflow to follow EF processes. These are the changes to https://www.openhwgroup.org/membership/#tab-membership:

• Remove all the bullet points and end this sentence with a period "Once you have chosen the level of membership (Platinum, Gold, Silver, or Supporter)."

• Add a sentence below (not in bold) "For detailed information review the Working Group Charter and
  Participation Agreement."

• The "Contact Us About Membership" form should link to a new page with the following form embedded:

<script charset="utf-8" type="text/javascript" src="//js.hsforms.net/forms/embed/v2.js"></script>
<script>
  hbspt.forms.create({
    portalId: "5413615",
    formId: "719da833-774d-4962-8ef3-985acd8d4df6"
  });
</script>

• A second button should be added beside "Contact Us About Membership" that says "My organisation is ready to join" and links to https://membership.eclipse.org/application/ready-to-join

On the other 3 tabs (https://www.openhwgroup.org/membership/#tab-benefits, https://www.openhwgroup.org/membership/#tab-levels and https://www.openhwgroup.org/membership/#tab-levels):

• Update the bottom buttons to the same "Contact Us About Membership" and "My organisation is ready to join" links.

CC @croundy