chore: Change '_' in long options to '-'.

On the command line, something like "--latexmk-cmd" looks nicer than
"--latexmk_cmd", though both are parsed identically by argparse.

Cherry-pick commit 0eba25b from feature-bash-completion branch.

src/tartex/_parse_args.py

@@ -101,15 +101,15 @@ def parse_args(args):
     # Latexmk options
     latexmk_opts = parser.add_argument_group("Options for latexmk processing")
     latexmk_opts.add_argument(
-        "--latexmk_tex",
+        "--latexmk-tex",
         choices=LATEXMK_TEX,
         default=None,
         help="Force TeX processing mode used by latexmk",
     )
 
     latexmk_opts.add_argument(
         "-F",
-        "--force_recompile",
+        "--force-recompile",
         action="store_true",
         help="Force recompilation even if .fls exists",
     )

src/tartex/tartex.py

@@ -415,7 +415,7 @@ def _do_tar(self, tar_obj):
                 tar_obj.add(dep)
             except FileNotFoundError:
                 log.warning(
-                    "Skipping INPUT file '%s' not found amongst sources, try"
+                    "Skipping INPUT file '%s', not found amongst sources; try"
                     " forcing a LaTeX recompile ('-F').",
                     dep,
                 )