readme: add some highlevel detail around the boot flow. #22635
| Job | Run time |
|---|---|
| 56m 13s | |
| 10m 1s | |
| 10m 54s | |
| 10m 4s | |
| 12m 17s | |
| 11m 32s | |
| 10m 33s | |
| 10m 54s | |
| 8m 52s | |
| 4m 41s | |
| 4m 42s | |
| 4m 6s | |
| 7m 24s | |
| 4m 44s | |
| 5m 51s | |
| 5m 7s | |
| 5m 4s | |
| 6m 4s | |
| 5m 14s | |
| 4m 55s | |
| 5m 55s | |
| 4m 51s | |
| 5m 48s | |
| 31m 37s | |
| 6m 38s | |
| 4m 4s | |
| 26s | |
| 4h 18m 31s |