fix: update default main repo location

Author: ojeytonwilliams

apps/api/sample.env

@@ -1,3 +1,5 @@
 CHALLENGE_EDITOR_CLIENT_LOCATION=http://localhost:3300
-# This assumes that the freeCodeCamp repo is located a sibling directory to the challenge-editor repo
-FCC_REPO_LOCATION=../../../freeCodeCamp
+# The location assumes that this repo is a submodule inside the main
+# freeCodeCamp repo at tools/challenge-editor. If that's not the case, this
+# path will need to be adjusted.
+FCC_REPO_LOCATION=../../../..