docs, remove 'guifontset' #11708

- remove redundant autocmd list
  This "grouped" list is useless, it only gets in the way when searching
  for event names.
- intro.txt: cleanup
- starting.txt: update, revisit
- doc: `:help bisect`
- mbyte.txt: update aliases 1656367b90. closes #11960
- options: remove 'guifontset'. Why:
  - It is complicated and is used by almost no one.
  - It is unlikely to be implemented by Nvim GUIs (complicated to parse,
    specific to Xorg...).

src/nvim/os/time.c

@@ -56,6 +56,8 @@ uint64_t os_now(void)
 
 /// Sleeps for `ms` milliseconds.
 ///
+/// @see uv_sleep() (libuv v1.34.0)
+///
 /// @param ms          Number of milliseconds to sleep
 /// @param ignoreinput If true, only SIGINT (CTRL-C) can interrupt.
 void os_delay(uint64_t ms, bool ignoreinput)
@@ -72,6 +74,8 @@ void os_delay(uint64_t ms, bool ignoreinput)
 
 /// Sleeps for `us` microseconds.
 ///
+/// @see uv_sleep() (libuv v1.34.0)
+///
 /// @param us          Number of microseconds to sleep.
 /// @param ignoreinput If true, ignore all input (including SIGINT/CTRL-C).
 ///                    If false, waiting is aborted on any input.