himalaya: fix config and add neovim wrapper

packages/vim-email.nix

@@ -0,0 +1,22 @@
+{
+  neovim,
+  vimPlugins,
+  writers,
+  ...
+}:
+let
+  vim-email = neovim.override {
+    extraName = "-email";
+    configure = {
+      customRC = ''
+        source ${./vim-kmein/shared.vim}
+        autocmd VimEnter * Himalaya
+      '';
+      packages.nvim.start = [
+        vimPlugins.telescope-nvim
+        vimPlugins.himalaya-vim
+      ];
+    };
+  };
+in
+  vim-email