docs: documented UpdateInformer usage that doesn't create cache file
#378
| Job | Run time |
|---|---|
| 38s | |
| 44s | |
| 54s | |
| 6s | |
| 34s | |
| 2m 26s | |
| 7s | |
| 40s | |
| 2m 26s | |
| 35s | |
| 46s | |
| 37s | |
| 45s | |
| 11m 18s |