chore: auto generate docs

doc/substitute-nvim.txt

@@ -273,14 +273,24 @@ EXCHANGE OPERATOR                          *substitute-nvim-exchange-operator*
 This operator allows to quickly exchange text inside a buffer.
 
 Eg. To exchange two words, place your cursor on the first word and type `sxiw`.
-Then move to the second word and type `sxiw` again. Note: the {motion} used in
-the first and second use of `sx` don’t have to be the same. Note 2: this is
-dot-repeatable, so you can use `.` instead of `sxiw` for the second word.
+Then move to the second word and type `sxiw` again.
+
+Note: the {motion} used in the first and second use of `sx` don’t have to be
+the same. Note 2: this is dot-repeatable, so you can use `.` instead of `sxiw`
+for the second word.
+
+You can select a whole line using the `line` function (`sxx` in the example
+below).
+
+Because this operator has to be invoked twice to change the document, if you
+change your mind after invoking the operator once, you can cancel you selection
+using the `cancel` function (mapped to `sxc` in the example below).
 
 >
     vim.api.nvim_set_keymap("n", "sx", "<cmd>lua require('substitute.exchange').operator()<cr>", { noremap = true })
     vim.api.nvim_set_keymap("n", "sxx", "<cmd>lua require('substitute.exchange').line()<cr>", { noremap = true })
-    vim.api.nvim_set_keymap("x", "X", "<cmd>lua require('substitute.exchange').visual()<cr>")
+    vim.api.nvim_set_keymap("x", "X", "<cmd>lua require('substitute.exchange').visual()<cr>", { noremap = true })
+    vim.api.nvim_set_keymap("n", "sxc", "<cmd>lua require('substitute.exchange').cancel()<cr>", { noremap = true })
 <
 
 
@@ -290,6 +300,7 @@ or
     nmap sx <cmd>lua require('substitute.exchange').operator()<cr>
     nmap sxx <cmd>lua require('substitute.exchange').line()<cr>
     xmap X <cmd>lua require('substitute.exchange').visual()<cr>
+    nmap sxc <cmd>lua require('substitute.exchange').cancel()<cr>
 <