pkg(nixvim): Add snack plugin for many little features

pkgs/nixvim/util/snacks.nix

@@ -0,0 +1,85 @@
+{...}: {
+  youthlic.plugins.snacks = {
+    enable = true;
+    luaConfig.content =
+      #lua
+      ''
+        -- Terminal Mappings
+        _M.__util_plugin_snacks_term_nav = function(direction)
+          ---@param self snacks.terminal
+          return function(self)
+            return self:is_floating() and "<c-" .. direction .. ">"
+              or vim.schedule(function()
+                vim.cmd.wincmd(direction)
+              end)
+          end
+        end
+      '';
+    settings = {
+      bigfile = {
+        enabled = true;
+      };
+      quickfile = {
+        enabled = true;
+      };
+      terminal = {
+        win = {
+          keys = {
+            nav_h = {
+              __unkeyed-1 = "<C-w>h";
+              __unkeyed-2 = {
+                __raw =
+                  #lua
+                  ''
+                    _M.__util_plugin_snacks_term_nav("h")
+                  '';
+              };
+              desc = "Go to Left Window";
+              expr = true;
+              mode = "t";
+            };
+            nav_j = {
+              __unkeyed-1 = "<C-w>j";
+              __unkeyed-2 = {
+                __raw =
+                  #lua
+                  ''
+                    _M.__util_plugin_snacks_term_nav("j")
+                  '';
+              };
+              desc = "Go to Lower Window";
+              expr = true;
+              mode = "t";
+            };
+            nav_k = {
+              __unkeyed-1 = "<C-w>k";
+              __unkeyed-2 = {
+                __raw =
+                  #lua
+                  ''
+                    _M.__util_plugin_snacks_term_nav("k")
+                  '';
+              };
+              desc = "Go to Upper Window";
+              expr = true;
+              mode = "t";
+            };
+            nav_l = {
+              __unkeyed-1 = "<C-w>l";
+              __unkeyed-2 = {
+                __raw =
+                  #lua
+                  ''
+                    _M.__util_plugin_snacks_term_nav("l")
+                  '';
+              };
+              desc = "Go to Right Window";
+              expr = true;
+              mode = "t";
+            };
+          };
+        };
+      };
+    };
+  };
+}