feat: split loadenv from readenv to load any file

cli/fish/config.fish

@@ -70,19 +70,23 @@ if status is-interactive
     # === auto cd into last activated directory
     test "$PWD" = "$HOME" && cd $last_pwd
 
+    function loadenv
+        while read -l line
+            set -l line (string trim $line)
+            if [ -z "$line" ]
+                continue
+            end
+            if string match -q '#*' $line
+                continue
+            end
+            set -l kv (string split -m 1 = -- $line)
+            set -gx $kv
+        end < $argv[1]
+    end
+
     function readenv --on-variable PWD
         if test -r .env
-            while read -l line
+            loadenv .env
-                set -l line (string trim $line)
-                if [ -z "$line" ]
-                    continue
-                end
-                if string match -q '#*' $line
-                    continue
-                end
-                set -l kv (string split -m 1 = -- $line)
-                set -gx $kv
-            end < .env
        end
     end
 end