docs(man): make subsections under FILES section

Signed-off-by: Masatake YAMATO <[email protected]>

Author: masatake

docs/man/ctags.1.rst

@@ -2153,12 +2153,18 @@ ENVIRONMENT VARIABLES
 FILES
 -----
 
+Output files
+~~~~~~~~~~~~
+
 ``tags``
 	The default tag file created by ctags.
 
 ``TAGS``
 	The default tag file created by etags.
 
+Preloading option files
+~~~~~~~~~~~~~~~~~~~~~~~
+
 ``$XDG_CONFIG_HOME/ctags/*.ctags``, or ``$HOME/.config/ctags/*.ctags`` if
 ``$XDG_CONFIG_HOME`` is not defined
 (on other than MS Windows)

man/ctags.1.rst.in

@@ -2153,12 +2153,18 @@ ENVIRONMENT VARIABLES
 FILES
 -----
 
+Output files
+~~~~~~~~~~~~
+
 ``tags``
 	The default tag file created by @CTAGS_NAME_EXECUTABLE@.
 
 ``TAGS``
 	The default tag file created by @ETAGS_NAME_EXECUTABLE@.
 
+Preloading option files
+~~~~~~~~~~~~~~~~~~~~~~~
+
 ``$XDG_CONFIG_HOME/ctags/*.ctags``, or ``$HOME/.config/ctags/*.ctags`` if
 ``$XDG_CONFIG_HOME`` is not defined
 (on other than MS Windows)