docs: optionlinks don't need the bars #35777

Problem:
Options links work even without vertical bars around them due to their
single quotes: the bars are unnecessary.

Solution:
Remove them.

src/nvim/api/buffer.c

@@ -54,7 +54,7 @@
 /// Unloaded Buffers: ~
 ///
 /// Buffers may be unloaded by the |:bunload| command or the buffer's
-/// |'bufhidden'| option. When a buffer is unloaded its file contents are freed
+/// 'bufhidden' option. When a buffer is unloaded its file contents are freed
 /// from memory and vim cannot operate on the buffer lines until it is reloaded
 /// (usually by opening the buffer again in a new window). API methods such as
 /// |nvim_buf_get_lines()| and |nvim_buf_line_count()| will be affected.

src/nvim/api/win_config.c

@@ -56,7 +56,7 @@
 /// provided or `win == 0`, a window will be created adjacent to the current window.
 /// If -1 is provided, a top-level split will be created. `vertical` and `split` are
 /// only valid for normal windows, and are used to control split direction. For `vertical`,
-/// the exact direction is determined by |'splitright'| and |'splitbelow'|.
+/// the exact direction is determined by 'splitright' and 'splitbelow'.
 /// Split windows cannot have `bufpos`/`row`/`col`/`border`/`title`/`footer`
 /// properties.
 ///