cookbook: Add "Time zone from tzdata rules" example

An example of parsing the rules from the tzdata (sometimes called "Olson
database") directly, and creating a Temporal.TimeZone object out of them.

Closes: #605

Author: ptomato

docs/cookbook-tzdata.md

@@ -0,0 +1,14 @@
+## Time zone directly from tzdata rules
+
+This is an example of building your own `Temporal.TimeZone` object from [tzdata-compatible rules](https://data.iana.org/time-zones/tz-how-to.html).
+
+This could be useful for testing, for example, or for using other versions of the tzdata than are installed on the host system.
+
+The code in this example is inefficient.
+In real production code, it would make more sense to load the data from a compiled form, not directly from the rules themselves.
+
+> **NOTE**: This is a very specialized use of Temporal and is not something you would normally need to do.
+
+```javascript
+{{cookbook/getTimeZoneObjectFromRules.mjs}}
+```

docs/cookbook.md

@@ -567,3 +567,9 @@ Extend `Temporal` to support arbitrarily-large years (e.g., **+635427810-02-02**
 Extend `Temporal` to support adjustment days for the Hijri calendars, which are sometimes required when the start of the month is based on astronomical observations.
 
 → [Adjustable Hijri calendar](hijri-days-adjustments.md)
+
+### Time zone directly from tzdata rules
+
+An example of building your own `Temporal.TimeZone` object from [tzdata-compatible rules](https://data.iana.org/time-zones/tz-how-to.html).
+
+→ [Time zone from tzdata](cookbook-tzdata.md)

docs/cookbook/all.mjs

@@ -17,6 +17,7 @@ import './getNextOffsetTransitionFromExactTime.mjs';
 import './getParseableZonedStringAtInstant.mjs';
 import './getSortedLocalDateTimes.mjs';
 import './getTimeStamp.mjs';
+import './getTimeZoneObjectFromRules.mjs';
 import './getTripDurationInHrMinSec.mjs';
 import './getUtcOffsetDifferenceSecondsAtInstant.mjs';
 import './getUtcOffsetSecondsAtInstant.mjs';