docs: remove unnecessary mini.ai recipe from vimdoc

Problem: the `*pending-mini-ai*` section assumed mini.ai intercepts
buffer-local `at`/`it`/`aC`/`iC` mappings, requiring a manual
`vim.b.miniai_config` workaround.

Solution: remove the section. Neovim's keymap resolver already
prioritizes longer buffer-local mappings over mini.ai's global
`a`/`i` handlers — no recipe needed.

doc/pending.txt

@@ -844,77 +844,6 @@ Event-driven statusline refresh: >lua
     })
 <
 
-mini.ai integration: ~                                        *pending-mini-ai*
-mini.ai (from mini.nvim) maps `a` and `i` as single-key handlers in
-operator-pending and visual modes. It captures the next keystroke internally
-rather than routing it through Neovim's mapping system, which means the
-buffer-local `at`, `it`, `aC`, and `iC` maps never fire for users who have
-mini.ai installed.
-
-The fix is to register pending.nvim's text objects as mini.ai custom
-textobjects via `vim.b.miniai_config` in a `FileType` autocmd. mini.ai's
-`custom_textobjects` spec expects each entry to be a function returning
-`{ from = { line, col }, to = { line, col } }` (1-indexed, col is
-byte-offset from 1).
-
-pending.nvim's `textobj.inner_task_range(line)` returns the start and end
-column offsets within the current line. Combine it with the cursor row and
-the buffer line to build the region tables mini.ai expects: >lua
-
-    vim.api.nvim_create_autocmd('FileType', {
-      pattern = 'pending',
-      callback = function()
-        local function task_inner()
-          local textobj = require('pending.textobj')
-          local row = vim.api.nvim_win_get_cursor(0)[1]
-          local line = vim.api.nvim_buf_get_lines(0, row - 1, row, false)[1]
-          if not line then return end
-          local s, e = textobj.inner_task_range(line)
-          if s > e then return end
-          return { from = { line = row, col = s }, to = { line = row, col = e } }
-        end
-
-        local function category_inner()
-          local textobj = require('pending.textobj')
-          local buffer = require('pending.buffer')
-          local meta = buffer.meta()
-          if not meta then return end
-          local row = vim.api.nvim_win_get_cursor(0)[1]
-          local header_row, last_row = textobj.category_bounds(row, meta)
-          if not header_row then return end
-          local first_task, last_task
-          for r = header_row + 1, last_row do
-            if meta[r] and meta[r].type == 'task' then
-              if not first_task then first_task = r end
-              last_task = r
-            end
-          end
-          if not first_task then return end
-          local first_line = vim.api.nvim_buf_get_lines(0, first_task - 1, first_task, false)[1] or ''
-          local last_line = vim.api.nvim_buf_get_lines(0, last_task - 1, last_task, false)[1] or ''
-          return {
-            from = { line = first_task, col = 1 },
-            to   = { line = last_task,  col = #last_line },
-          }
-        end
-
-        vim.b.miniai_config = {
-          custom_textobjects = { t = task_inner, C = category_inner },
-        }
-      end,
-    })
-<
-
-Note that the default `keymaps.a_task = 'at'` and friends still work in
-standard Neovim operator-pending mode for users who do not have mini.ai. The
-`vim.b.miniai_config` block is only needed when mini.ai is active.
-
-`aC` (outer category) is not exposed here because mini.ai does not support
-the linewise selection that `aC` requires. Use the buffer-local `aC` key
-directly, or disable `a_category` in `keymaps` and handle it via a
-`vim.b.miniai_config` entry that returns a linewise region if mini.ai's
-spec allows it in your version.
-
 Nerd font icons: >lua
     vim.g.pending = {
       icons = {