Document the convenience function `measure`

[doc only]

docs/user/user/metrics/timespan.md

@@ -57,6 +57,14 @@ fun onLoginCancel() {
 }
 ```
 
+For convenience one can measure the time of a function or block of code:
+
+```Kotlin
+Auth.loginTime.measure {
+    // Process login flow
+}
+```
+
 The time reported in the telemetry ping will be timespan recorded during the lifetime of the ping.
 
 There are test APIs available too:
@@ -136,6 +144,14 @@ func onLoginCancel() {
 }
 ```
 
+For convenience one can measure the time of a function or block of code:
+
+```Kotlin
+Auth.loginTime.measure {
+    // Process login flow
+}
+```
+
 The time reported in the telemetry ping will be timespan recorded during the lifetime of the ping.
 
 There are test APIs available too:

docs/user/user/metrics/timing_distribution.md

@@ -69,6 +69,14 @@ fun onPageLoaded(e: Event) {
 }
 ```
 
+For convenience one can measure the time of a function or block of code:
+
+```Kotlin
+Pages.pageLoad.measure {
+    // Load a page
+}
+```
+
 There are test APIs available too.  For convenience, properties `sum` and `count` are exposed to facilitate validating that data was recorded correctly.
 
 Continuing the `pageLoad` example above, at this point the metric should have a `sum == 11` and a `count == 2`:
@@ -152,6 +160,15 @@ func onPageLoaded() {
 }
 ```
 
+For convenience one can measure the time of a function or block of code:
+
+```Swift
+Pages.pageLoad.measure {
+    // Load a page
+}
+```
+
+
 There are test APIs available too.  For convenience, properties `sum` and `count` are exposed to facilitate validating that data was recorded correctly.
 
 Continuing the `pageLoad` example above, at this point the metric should have a `sum == 11` and a `count == 2`: