[Docs] help2man man-page generation is missing a [DESCRIPTION] section

[nktnet1]

In lib/help2man_include.txt, there is no [DESCRIPTION] section.

Here is what it used to look like on CSE machines (v2.7.8, running man dcc):

DESCRIPTION
       -fsanitize=<sanitizer1,sanitizer2>
              run two sanitizers (default -fsanitize=address,valgrind) The second sanitizer is a separate process.  The synchroni‐
              sation of the 2 processes should be effective for most use of the standard C  library  and  hence  should  work  for
              novice programmers.  If synchronisation is lost the 2nd sanitizer terminates silently.

       -fsanitize=<sanitizer>
              check  for  runtime  errors using using a single sanitizer which can be one of address       - AddressSanitizer, in‐
              valid memory operations valgrind      - valgrind, primarily uninitialized variables memory        - MemorySanitizer,
              primarily uninitialized variables

       --leak-check
              check for memory leaks, requires --fsanitizer=valgrind to intercept errors

       --no-explanations
              do not add explanations to compile-time error messages

       --no-shared-libasan
              do not use libasan

       --ifdef
              use ifdef instead of ld's -wrap option

Since help2man relies on dcc's --version and --help options:

dcc/Makefile

Lines 23 to 24 in f41dca3

	dcc.1: dcc lib/help2man_include.txt
	help2man --include=lib/help2man_include.txt ./dcc >dcc.1

but the --help option is outputting nothing:

dcc/compile_time_python/options.py

Lines 390 to 392 in f41dca3

	elif arg == "--help":
	print()
	sys.exit(0)

we end up with a man page that looks like this:

DCC(1)                                                      User Commands                                                      DCC(1)

NAME
       dcc - manual page for dcc version 2.34

DESCRIPTION
ENVIRONMENT
       DCC_DEBUG level of debugging output

EXAMPLES
           $ dcc buffer_overflow.c
           $ ./a.out
           a.c:6:3: runtime error: index 10 out of bounds for type 'int [10]'
           
          ... truncated ...