Troublshooting: Section on thirdy-party API logging

Troubleshooting.md

@@ -38,6 +38,26 @@ You won't be redirected to Frontier's authentication website and can't edit your
 - The last time you ran Elite: Dangerous you didn't enter the game. You will be able to edit these values once you've entered the game.
 - Your “E:D journal file location” setting is incorrect. See [below](#doesnt-auto-update-andor-persistently-gives-server-is-lagging-error).
 
+## Help - a plugin is spamming errors in the log
+
+The EDSM and Inara internal plugins communicate with their respective
+sites and might under some circumstances report what look like errors,
+but are really just messages for information.
+
+Examples include:
+
+ * `EDSM 402 Item unknown {"Periapsis": 0.0,"_systemCoordinates": [-33300.0,19.5625,3139.5],"BodyName": "Byeia Thoea JI-K c8-0 4 A Ring","...`
+    EDSM is/wasn't recording Ring data, so tells us this.  It's
+    harmless.
+ * `Inara   400 No reputation value provided.       {"eventName": "setCommanderReputationMajorFaction", "eventTimestamp": "2020-07-15T15:32:42Z", "eventData": []}`
+    Inara doesn't like the application trying to send an empty list of
+    Major Faction (Empire, Federation, Alliance) reputations.  It's
+    harmless.
+
+Please
+[report](https://github.com/EDCD/EDMarketConnector/issues/new/choose)
+any other such messages you see in your logs so we can document them
+here and/or fix the EDMC code.
 
 ---
 # Firewall and Network Issues