dev: better direnv

Override caelestia command with dev version instead of using ./run.sh
Allows completions to work

.envrc

@@ -1 +1,5 @@
+if has nix; then
     use flake
+fi
+
+PATH_add bin

bin/caelestia

@@ -2,6 +2,6 @@
 
 # Utility script for running caelestia
 
-cd "$(dirname $0)/src" || exit
+cd "$(dirname $0)/../src" || exit
 
 python -m caelestia "$@"