ldconfig.8: ffix

ldconfig.8: ffix

* Set page topic in lowercase.
* Rewrite synopses to use groff man(7) `SY`/`YS` extension macros.
* Rewrite synopses to use man(7) font macros instead of *roff font
  selection escape sequences.
* In synopses, set ellipses as separate "operands" to better suggest
  argument separation by white space.
* In synopses, prevent breaks within option brackets.
* Typeset ellipses more attractively on troff devices.
* Rewrite option list to use man(7) font macros instead of *roff font
  selection escape sequences.
* Use groff man(7) `TQ` extension macro to include multiple tags for
  options with long synonyms instead of comma notation.
* Set literals used as arguments to `-c` option in bold, not italics.

Signed-off-by: G. Branden Robinson <g.branden.robinson@gmail.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>