Updates to https://ecdtools.eclipse.org/

Two updates we should have done some time ago.

• On the 'Resources' pull down, remove the 'CDT Cloud SIG' entry. But leave the page it points to. We may want later to retrieve some of that content.
• On the https://ecdtools.eclipse.org/membership/ page, because we've flattened the member structure, change this sentence, Join industry leaders like Arm, Ericsson, Obeo, Red Hat, and ST as we define and build the future of web and cloud development tools. to Join industry leaders as we define and build the future of web and cloud development tools. I'm thinking we also link industry leaders to the Members section a little further down the page.