Hourly scheduled builds via a ??:MM slot

`atTimes: ["??:05"]` runs a build five past every hour. The pattern expands
to its 24 concrete slots before the due-slot match, so each hour is its own
slot in the trigger state and fires once — the existing per-slot semantics
carry over unchanged, including that only the latest due slot of a day
triggers and that a slot whose pool is still building is retried until it
starts.

Only the hour may be a wildcard; anything else is skipped with a warning.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/main/kotlin/de/hoennig/gittally/commands/InitCommand.kt

@@ -162,7 +162,7 @@ class InitCommand(
               # Example definition — triggers (onPush/atTimes), branch selector
               # (branches/activeWithin), and overrides of the branch settings:
               # pitest:
-              #   atTimes: ["01:00"]           # daily UTC times HH:MM
+              #   atTimes: ["01:00"]           # daily UTC times HH:MM ("??:05" = every hour at :05)
               #   branches: ["master"]         # names or glob patterns; default: all branches
               #   activeWithin: 24h            # only branches with recent commits
               #   buildCommand: ./gradlew piTestFull