feat: doc updates and cleanups

doc/fugitive-ts.nvim.txt

@@ -62,6 +62,10 @@ CONFIGURATION                                               *fugitive-ts-config*
                              Vim syntax highlighting options (experimental).
                              See |fugitive-ts.VimConfig| for fields.
 
+        {diffsplit}           (table, default: see below)
+                             Diffsplit highlighting options.
+                             See |fugitive-ts.DiffsplitConfig| for fields.
+
         {highlights}         (table, default: see below)
                              Controls which highlight features are enabled.
                              See |fugitive-ts.Highlights| for fields.
@@ -90,6 +94,15 @@ CONFIGURATION                                               *fugitive-ts-config*
                              this many lines. Lower than the treesitter default
                              due to the per-character cost of |synID()|.
 
+                                                 *fugitive-ts.DiffsplitConfig*
+    Diffsplit config fields: ~
+        {enabled}            (boolean, default: true)
+                             Override diff highlight foreground colors in
+                             |:Gdiffsplit| and |:Gvdiffsplit| windows so
+                             treesitter syntax is visible through the diff
+                             backgrounds. Uses window-local 'winhighlight'
+                             and only applies to fugitive-owned buffers.
+
                                                        *fugitive-ts.Highlights*
     Highlights table fields: ~
         {background}         (boolean, default: true)

lua/fugitive-ts/init.lua

@@ -352,6 +352,15 @@ function M.setup(opts)
       end
     end,
   })
+
+  vim.api.nvim_create_autocmd('WinClosed', {
+    callback = function(args)
+      local win = tonumber(args.match)
+      if win and diff_windows[win] then
+        diff_windows[win] = nil
+      end
+    end,
+  })
 end
 
 return M