Remove some internal information in use counter doc.

Bug: b/283545491
Change-Id: I5ae8f0649cf5ade6e61ec8a6a40558832b7d016a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4883772
Reviewed-by: Annie Sullivan <sullivan@chromium.org>
Commit-Queue: Annie Sullivan <sullivan@chromium.org>
Auto-Submit: Robert Kaplow <rkaplow@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1199823}

docs/use_counter_wiki.md

@@ -85,33 +85,17 @@ page visits):
 + For the most dominant milestone.
 
 
-### UMA Timeline with Formula
+### Internal UMA tools
 
-Internally (sorry, Google employees only) you can query the usage of a feature
-with break-downs on platforms, channels, etc on the
-[UMA Timeline dashboard](https://goto.google.com/uma-usecounter).
+See (https://goto.google.com/uma-usecounter) for internal tooling.
 
-To create break-downs, select filters on the top of the dashboard, for example,
-"Platform", and set the `operation` to "split by". Note that you can also see
-data usage within Android Webview by setting a filter on "Platform".
-
-Select Metric:
+Some metrics of interest:
 + "Blink.UseCounter.Features" for HTML and JavaScript features.
 + "Blink.UseCounter.CSSProperties" for CSS properties.
 + "Blink.UseCounter.AnimatedCSSProperties" for animated CSS properties.
 + "Blink.UseCounter.Extensions.Features" for HTML and JacaScript features on
   extensions.
 
-In the metric panel, select "Formula" in the left-most drop-down. Then Click
-"ADD NEW FORMULA" with:
-```
-"MyFeature" / "PageVisits" * 100
-```
-
-This provides timeline data for your feature usage (per page load) with
-break-downs, which should more or less reflects the results on chromestatus.com.
-
-
 ### UseCounter Feature in HTTP Archive
 
 HTTP Archive crawls the top 10K sites on the web and records everything from