Remove unnecessary images in perf bar doc

doc/administration/monitoring/performance/performance_bar.md

@@ -18,25 +18,20 @@ From left to right, it displays:
 - **Current Host**: the current host serving the page.
 - **Database queries**: the time taken (in milliseconds) and the total number
   of database queries, displayed in the format `00ms / 00 (00 cached) pg`. Click to display
-  a modal window with more details:
-  ![SQL profiling using the Performance Bar](img/performance_bar_sql_queries.png)
+  a modal window with more details.
 - **Gitaly calls**: the time taken (in milliseconds) and the total number of
   [Gitaly](../../gitaly/index.md) calls. Click to display a modal window with more
-  details:
-  ![Gitaly profiling using the Performance Bar](img/performance_bar_gitaly_calls.png)
+  details.
 - **Rugged calls**: the time taken (in milliseconds) and the total number of
   [Rugged](../../nfs.md#improving-nfs-performance-with-gitlab) calls.
-  Click to display a modal window with more details:
-  ![Rugged profiling using the Performance Bar](img/performance_bar_rugged_calls.png)
+  Click to display a modal window with more details.
 - **Redis calls**: the time taken (in milliseconds) and the total number of
-  Redis calls. Click to display a modal window with more details:
-  ![Redis profiling using the Performance Bar](img/performance_bar_redis_calls.png)
+  Redis calls. Click to display a modal window with more details.
 - **Elasticsearch calls**: the time taken (in milliseconds) and the total number of
   Elasticsearch calls. Click to display a modal window with more details.
 - **External HTTP calls**: the time taken (in milliseconds) and the total
   number of external calls to other systems. Click to display a modal window
-  with more details
-  ![External call details in the Performance Bar](img/performance_bar_external_http_calls.png)
+  with more details.
 - **Load timings** of the page: if your browser supports load timings (Chromium
   and Chrome) several values in milliseconds, separated by slashes.
   Click to display a modal window with more details. The values, from left to right:
@@ -44,8 +39,7 @@ From left to right, it displays:
   - [**First Contentful Paint**](https://web.dev/first-contentful-paint/):
     Time until something was visible to the user.
   - [**DomContentLoaded**](https://developers.google.com/web/fundamentals/performance/critical-rendering-path/measure-crp) Event.
-  - **Total number of requests** the page loaded:
-    ![Frontend requests using the Performance Bar](img/performance_bar_frontend.png)
+  - **Total number of requests** the page loaded.
 - **Trace**: If Jaeger is integrated, **Trace** links to a Jaeger tracing page
   with the current request's `correlation_id` included.
 - **+**: A link to add a request's details to the performance bar. The request
@@ -60,21 +54,18 @@ From left to right, it displays:
 
 ## Request warnings
 
-Requests exceeding predefined limits display a warning **{warning}** icon and
-explanation next to the failing metric. In this example, the Gitaly call duration
-exceeded the threshold:
+Requests that exceed predefined limits display a warning **{warning}** icon and
+explanation next to the metric. In this example, the Gitaly call duration
+exceeded the threshold.
 
 ![Gitaly call duration exceeded threshold](img/performance_bar_gitaly_threshold.png)
 
 If any requests on the current page generated warnings, the warning icon displays
-next to the **Request selector**:
+next to the **Requests** selector menu. In this selector menu, an exclamation `(!)`
+appears next to requests with warnings.
 
 ![Request selector showing two requests with warnings](img/performance_bar_request_selector_warning.png)
 
-Requests with warnings display `(!)` after their path in the **Request selector**:
-
-![Request selector showing dropdown](img/performance_bar_request_selector_warning_expanded.png)
-
 ## Enable the Performance Bar via the Admin Area
 
 The GitLab Performance Bar is disabled by default. To enable it for a given group: