Clarified docs regarding verifying correct telemetry somewhat

docs/TESTPLAN.md

@@ -112,10 +112,10 @@ No user interface elements are modified in this study.
 
 ### Note: checking "sent Telemetry is correct"
 
-- Open the Browser Console using Firefox's top menu at `Tools > Web Developer > Browser Console`. This will display Shield (loading/telemetry) log output from the add-on.
+- Open the Browser Console using Firefox's top menu at `Tools > Web Developer > Browser Console`. This will display Shield (loading/telemetry) log output from the add-on as long as the preference `shieldStudy.logLevel` is specified, with varying output as per below: 
-- To get an idea of how often telemetry is sent and calculated ping sizes, set `shieldStudy.logLevel` to `log`. This permits log-level shield-add-on log output in the browser console which includes high-level log messages regarding sent telemetry payloads.
+  - To get an idea of how often telemetry is sent and their calculated ping sizes, set `shieldStudy.logLevel` to `log`. This permits log-level shield-add-on log output in the browser console which includes high-level log messages regarding sent telemetry payloads.
-- To get an idea of how often [OpenWPM](https://github.com/mozilla/openwpm-webext-instrumentation) instruments a JS/HTTP/COOKIE event, set `shieldStudy.logLevel` to `info`. This permits info-level shield-add-on log output in the browser console which includes high-level log messages regarding received OpenWPM packages.
+  - To get an idea of how often [OpenWPM](https://github.com/mozilla/openwpm-webext-instrumentation) instruments a JS/HTTP/COOKIE event, set `shieldStudy.logLevel` to `info`. This permits info-level shield-add-on log output in the browser console which includes high-level log messages regarding received OpenWPM packages.
-- To inspect the unencrypted contents individual telemetry packets, set `shieldStudy.logLevel` to `all`. This permits debug-level shield-add-on log output in the browser console. Note that this will negatively affect the performance of Firefox.
+  - To inspect the unencrypted contents individual telemetry packets, set `shieldStudy.logLevel` to `all`. This permits debug-level shield-add-on log output in the browser console. Note that this will negatively affect the performance of Firefox.
 - To see the actual (encrypted) payloads, go to `about:telemetry` -> Click `current ping` -> Select `Archived ping data` -> Ping Type `pioneer-study` -> Choose a payload -> Raw Payload
 
 See [TELEMETRY.md](./TELEMETRY.md) for more details on what pings are sent by this add-on.