Problem: pkgs/update.sh is cwd-sensitive
Problem: pkgs/update.sh is cwd-sensitive

Solution: Make it cd to the containing directory

Now you can run ./pkgs/update.sh and get fractalide.nix in the right
place.

fractalide/fractalide,sjmackenzie/fractalide,dmichiels/fractalide,dmichiels/fractalide,fractalide/fractalide,dmichiels/fractalide,sjmackenzie/fractalide,sjmackenzie/fractalide,fractalide/fractalide