Convert \\subsection sections into rst format

sphinx_doc_src/cmds/psub.rst

@@ -7,7 +7,8 @@ Synopsis
 COMMAND1 ( COMMAND2 | psub [-F | --fifo] [-f | --file] [-s SUFFIX])
 
 
-\subsection psub-description Description
+Description
+------------
 
 Some shells (e.g., ksh, bash) feature a syntax that is a mix between command substitution and piping, called process substitution. It is used to send the output of a command into the calling command, much like command substitution, but with the difference that the output is not sent through commandline arguments but through a named pipe, with the filename of the named pipe sent as an argument to the calling program. `psub` combined with a regular command substitution provides the same functionality.
 
@@ -19,7 +20,8 @@ The following options are available:
 
 - `-s` or `--suffix` will append SUFFIX to the filename.
 
-\subsection psub-example Example
+Example
+------------
 
 \fish
 diff (sort a.txt | psub) (sort b.txt | psub)