docs(guide): add a Series / cup tab to the in-app guide

Explains creating a series, running each round from the series page,
points and standings, and a worked winter-series example.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "rc-racecore",
-  "version": "1.37.0",
+  "version": "1.37.1",
   "private": true,
   "description": "RC RaceCore live timing and race control with AMMC ingest and SQLite persistence",
   "engines": {