Add Sparkplug specification pages to the website

We need a new top menu option and a few simple web pages to be added to the Sparkplug website to provide access to information about the specification and the specification committee. Those closely resemble what can be found in the Jakarta.ee website and do not require any special styling apart from headers and tables.

The top menu option should be named "Specification," It should be added between "Resources " and "Compatibility."

The specification menu option should lead to a page called " The Sparkplug specification" The first half of this page will contain text describing Sparkplug and listing the spec versions. Initially, the only version listed will be Sparkplug v3.0.

The second half of the page will be under a "Specification Committee" header. It will contain the composition of the spec committee as found on this equivalent Jakarta page: https://jakarta.ee/committees/specification/. We will need to provide access to PDFs of the committee's minutes like Jakarta does.

We will also need a specific page about the Sparkplug v3.0 release, similar to https://jakarta.ee/specifications/platform/10/. It will be linked from the main "Specification" page.

This Google doc contains preliminary content for the new pages described above. https://docs.google.com/document/d/1Zs7T0KxX-dPQRa9RN-8b8_vOhKHx03DIeJzK3wiQb-g

We also need a page for the TCK process, which is linked from the "Specification" page. The Draft TCK process is contained in this Google Doc: https://docs.google.com/document/d/1NuhACX1evbmT4kTPGuagTchAsNSM1NnUFRwnbIkwem4

Thank you in advance for your support!