envrc: revert deleted line (#3452)

It was deleted in a bad rebase.

.envrc

@@ -1,9 +1,9 @@
 ### General env vars ###
 export WORKSPACE_ROOT=$(pwd)
-export RUST_LOG_FORMAT=devel
+export RUST_LOG_FORMAT=devel # QE specific
 export RUST_LOG=info
 
-### Various local dev env vars ###
+### Various query engine local dev env vars ###
 export PRISMA_DML_PATH=$(pwd)/dev_datamodel.prisma
 export PRISMA2_BINARY_PATH="/usr/local/lib/node_modules/prisma2/"
 export PRISMA_BINARY_PATH=$(pwd)/target/release/query-engine
@@ -18,6 +18,7 @@ export SIMPLE_TEST_MODE="yes" # Reduces the amount of generated `relation_link_t
 
 ### QE specific logging vars ###
 export QE_LOG_LEVEL=debug # Set it to "trace" to enable query-graph debugging logs
+# export PRISMA_RENDER_DOT_FILE=1 # Uncomment to enable rendering a dot file of the Query Graph from an executed query.
 # export FMT_SQL=1 # Uncomment it to enable logging formatted SQL queries
 
 # Mongo image requires additional wait time on arm arch for some reason.