user/direnv: clear cache on activation

also changed the layout name to be a bit easier to find if need be

res/direnvrc

@@ -4,5 +4,7 @@ direnv_layout_dir() {
     echo "${direnv_layout_dirs[$PWD]:=$(
         echo -n "$XDG_CACHE_HOME"/direnv/layouts/
         echo -n "$PWD" | shasum | cut -d ' ' -f 1
+        echo -n "-"
+        basename $PWD
     )}"
 }