Add custom plugin markview

lua/custom/plugins/init.lua

@@ -2,4 +2,35 @@
 --  I promise not to create any merge conflicts in this directory :)
 --
 -- See the kickstart.nvim README for more information
-return {}
+return {
+    {
+        'OXY2DEV/markview.nvim',
+        lazy = false, -- Recommended
+        -- ft = "markdown" -- If you decide to lazy-load anyway
+  
+        dependencies = {
+            'nvim-treesitter/nvim-treesitter',
+            'nvim-tree/nvim-web-devicons',
+        },
+
+        opts = {
+            initial_state = false,
+        },
+        config = function(_, opts)
+            require('markview').setup(opts)
+  
+            local splitToggle_state = false
+            vim.keymap.set('n', '<C-ö>', function()
+                if not splitToggle_state then
+                    -- The split toggle will not work unless markview is disabled in the initial window beforehand
+                    vim.cmd 'Markview disableAll'
+                    vim.cmd 'Markview splitEnable'
+                    splitToggle_state = true
+                else
+                    vim.cmd 'Markview splitDisable'
+                    splitToggle_state = false
+                end
+            end, { silent = true, desc = 'Toggle Markview split view' })
+        end,
+    },
+}