Tournaments

Tournament announcements and history.
TODO: figure out how to incorporate Calendar system.
PLAN: sections for:
* List of tournaments by name (canonical list).
* List of tournaments by region (in what order?).
* List of tournaments by date (most imminent first).
* List of tournaments by expected turnout (largest first).
* Past tournaments and their results.
PLAN: generalized tournament info, e.g. checklists, how-to run, rulesets.