Revert "Use helix throughout"

This reverts commit 3e0bc5c.

home/fish.nix

@@ -37,7 +37,7 @@ in
         # centralise where python puts its .pyc files
         set -x PYTHONPYCACHEPREFIX {$HOME}/.python-cache
 
-        set -x EDITOR "${pkgs.helix}/bin/hx"
+        set -x EDITOR "${neovim}/bin/nvim"
         set -x PAGER "${pkgs.bat}/bin/bat"
 
         # host-specific configuration
@@ -155,8 +155,6 @@ in
       trash = "${pkgs.python3Packages.send2trash}/bin/send2trash";
       tree = "${pkgs.eza}/bin/eza -T";
       vup = "${neovim}/bin/nvim --headless -c 'autocmd User PackerComplete quitall' -c 'PackerSync'";
-      vim = "${pkgs.helix}/bin/hx";
-      nvim = "${pkgs.helix}/bin/hx";
     } // lib.optionalAttrs isLinux {
       pbcopy = "${pkgs.xclip}/bin/xclip -selection clipboard";
       pbpaste = "${pkgs.xclip}/bin/xclip -selection clipboard -o";

home/git.nix

@@ -125,7 +125,7 @@
         autocrlf = "input";
         safecrlf = true;
         whitespace = "fix";
-        editor = "${pkgs.helix}/bin/hx";
+        editor = "nvim";
         mergeoptions = "--no-ff";
         preloadindex = true;
         ignorecase = false;

home/neovim.nix

@@ -2,6 +2,10 @@
 {
   programs.neovim = {
     enable = true;
+    viAlias = true;
+    vimAlias = true;
+    vimdiffAlias = true;
+    defaultEditor = true;
     withPython3 = true;
     extraPython3Packages = (ps: with ps; [
       pynvim