Improve OVAL Leadership Board-related process documentation

[DavidRies]

The current OVAL Leadership Board process documentation is not complete. Not all of the processes were migrated from the legacy MITRE pages (see here and here).

The current OVAL Leadership Board process documentation covers:

• description of the role
• listing of various the members
• documentation of responsibilities
• the appointment process

However, we failed to migrate over several details from the MITRE pages, for example:

• who may vote
• announcing a vote
• quorum
• role changes
• etc.

I suggest we migrate the relevant/missing MITRE documentation over to our current site for clarity and completeness, without changing any of the missing rules/processes themselves.

In the absence of feedback to the contrary, I will follow the current proposal process and create a PR to effect this.

[adammontville]

Thanks for bringing posting this issue and taking the ball, David. No objection to migrating the relevant/missing MITRE documentation to our current site.