promtail: Fix title and image path on `logrotation` doc (#8208)

Signed-off-by: Kaviraj <kavirajkanagaraj@gmail.com>

**What this PR does / why we need it**:
This fixes
1. Missing UI link to the side panel
2. Image paths


![Screenshot_2023-01-19_10-04-58](https://user-images.githubusercontent.com/3735252/213400320-66061f0d-dbbc-4024-a666-f2b0830f2227.png)

![Screenshot_2023-01-19_10-04-40](https://user-images.githubusercontent.com/3735252/213400323-b786765a-4c5d-4b23-ad98-70cec030a202.png)


**Which issue(s) this PR fixes**:
Fixes #NA

**Special notes for your reviewer**:

**Checklist**
- [x] Reviewed the
[`CONTRIBUTING.md`](https://github.com/grafana/loki/blob/main/CONTRIBUTING.md)
guide (**required**)
- [x] Documentation added

Signed-off-by: Kaviraj <kavirajkanagaraj@gmail.com>
Co-authored-by: Danny Kopping <danny.kopping@grafana.com>

docs/sources/clients/promtail/logrotation.md

@@ -1,9 +1,12 @@
+---
+title: Promtail and Log Rotation
+---
 # Promtail and Log Rotation
 
 ## Why does log rotation matters?
 
 At any point in time, there may be three processes working on a log file as shown in the image below.
-![block_diagram](./logrotation-components.png)
+![block_diagram](../logrotation-components.png)
 
 1. Appender - A writer that keeps appending to a log file. This can be your application or some system daemons like Syslog, Docker log driver or Kubelet, etc.
 2. Tailer - A reader that reads log lines as they are appended, for example, agents like Promtail.
@@ -25,10 +28,10 @@ In both cases, after log rotation, all new log lines are written to the original
 These two methods of log rotation are shown in the following images.
 
 ### Copy and Truncate
-![block_diagram](./logrotation-copy-and-truncate.png)
+![block_diagram](../logrotation-copy-and-truncate.png)
 
 ### Rename and Create
-![block_diagram](./logrotation-rename-and-create.png)
+![block_diagram](../logrotation-rename-and-create.png)
 
 Both types of log rotation seem to give the same result. However, there are some subtle differences.