docs: update pitr readme

[codecov-commenter]

Codecov Report

Attention: 916 lines in your changes are missing coverage. Please review.

Comparison is base (3604a24) 39.71% compared to head (6da6a7e) 36.79%. Report is 247 commits behind head on main.

Files	Patch %	Lines
...phere-operator/pkg/controllers/chaos_controller.go	0.00%	276 Missing :warning:
...perator/pkg/controllers/storage_node_controller.go	26.58%	96 Missing and 20 partials :warning:
...operator/pkg/controllers/auto_scaler_controller.go	0.00%	89 Missing :warning:
pitr/agent/internal/pkg/opengauss.go	5.61%	84 Missing :warning:
pitr/cli/internal/cmd/delete.go	67.45%	43 Missing and 12 partials :warning:
pitr/cli/pkg/prettyoutput/progress.go	8.51%	43 Missing :warning:
pitr/cli/internal/pkg/local-storage.go	11.11%	37 Missing and 3 partials :warning:
...ator/cmd/shardingsphere-operator/manager/option.go	6.06%	31 Missing :warning:
pitr/cli/internal/cmd/backup.go	74.78%	28 Missing and 2 partials :warning:
pitr/cli/internal/cmd/common.go	77.77%	16 Missing and 8 partials :warning:
... and 12 more

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #484 +/- ## ========================================== - Coverage 39.71% 36.79% -2.93% ========================================== Files 51 60 +9 Lines 6083 6950 +867 ========================================== + Hits 2416 2557 +141 - Misses 3448 4146 +698 - Partials 219 247 +28 ```

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[sonarcloud[bot]]

Quality Gate passed

Kudos, no new issues were introduced!

0 New issues
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud