Make spellcheck happy [doc only]

.dictionary

@@ -205,6 +205,7 @@ subcommand
 subpath
 subprocess
 subprocesses
+substring
 swiftlint
 tcsh
 templating
@@ -215,6 +216,7 @@ timezones
 toolchain
 toolchains
 tooltip
+tooltips
 transpiler
 travis
 und

docs/user/user/debugging/index.md

@@ -26,7 +26,7 @@ If nothing is showing up on the dashboard after you set a `debugViewTag` and you
 `Glean must be enabled before sending pings.` in the logs, Glean is disabled. Check with
 the application author on how to re-enable it.
 
-### Soure Tags
+### Source Tags
 
 Tags outgoing pings with a maximum of 5 comma-separated tags.
 

docs/user/user/debugging/ios.md

@@ -14,7 +14,7 @@ For debugging and validation purposes on iOS, the Glean SDK makes use of a custo
 
 ### Available commands and query format
 
-All 4 Glean debuging features are available through the custom URL scheme tool.
+All 4 Glean debugging features are available through the custom URL scheme tool.
 
 - [`logPings`](../../referece/debugging/logPings.md): This is either true or false and will cause pings that are submitted to also be echoed to the device's log.
 - [`debugViewTag`](../../referece/debugging/debugViewTag.md): This command will tag outgoing pings with the provided value, in order to identify them in the Glean Debug View.