Move env from .zshrc_local to .zshenv

.zshenv is loaded also for non-interactive shells, which is quite
useful for tokens etc

modules/home.nix

@@ -4,6 +4,7 @@
     git
     vim
     stow
+    wget
   ];
 
   programs.zsh = {
@@ -22,6 +23,15 @@
         . ${../migrated/.zshrc}
       fi
     '';
+
+    # At least have the following in .zshenv_local:
+    #   export GIT_AUTHOR_NAME='Alfred Muster'
+    #   export GIT_AUTHOR_EMAIL='test@example.com'
+    #   export GIT_COMMITTER_NAME="${GIT_AUTHOR_NAME?}"
+    #   export GIT_COMMITTER_EMAIL="${GIT_AUTHOR_EMAIL?}"
+    envExtra = ''
+      [ -r ~/.zshenv_local ] && source ~/.zshenv_local || true
+    '';
   };
 
   programs.home-manager.enable = true;