feat(cli): add `-f`/`-t`; hide `-if`/`-of` in help

`-f`/`--from` and `-t`/`--to` copy Pandoc and iconv(1).

`-if` and `-of` (with a single dash) are legacy options
from the Go days of Remarshal.
They are long overdue for hiding.

README.md

@@ -74,7 +74,7 @@ options:
   -v, --version         show program's version number and exit
   -i input, --input input
                         input file
-  --if {cbor,json,msgpack,toml,yaml}, -if {cbor,json,msgpack,toml,yaml}, --input-format {cbor,json,msgpack,toml,yaml}
+  --if {cbor,json,msgpack,toml,yaml}, --input-format {cbor,json,msgpack,toml,yaml}, -f {cbor,json,msgpack,toml,yaml}, --from {cbor,json,msgpack,toml,yaml}
                         input format
   --json-indent n, --indent-json n
                         JSON indentation
@@ -84,7 +84,7 @@ options:
                         1000000, negative for unlimited)
   -o output, --output output
                         output file
-  --of {cbor,json,msgpack,toml,yaml}, -of {cbor,json,msgpack,toml,yaml}, --output-format {cbor,json,msgpack,toml,yaml}
+  --of {cbor,json,msgpack,toml,yaml}, --output-format {cbor,json,msgpack,toml,yaml}, -t {cbor,json,msgpack,toml,yaml}, --to {cbor,json,msgpack,toml,yaml}
                         output format
   -s, --sort-keys       sort JSON, TOML, YAML keys instead of preserving key
                         order

remarshal.py

@@ -118,13 +118,21 @@ def _parse_command_line(argv: List[str]) -> argparse.Namespace:  # noqa: C901.
     if not format_from_argv0:
         parser.add_argument(
             "--if",
-            "-if",
             "--input-format",
+            "-f",
+            "--from",
             dest="input_format",
             default="",
             help="input format",
             choices=FORMATS,
         )
+        parser.add_argument(
+            "-if",
+            dest="input_format",
+            default="",
+            help=argparse.SUPPRESS,
+            choices=FORMATS,
+        )
 
     if not format_from_argv0 or argv0_to == "json":
         parser.add_argument(
@@ -175,13 +183,21 @@ def _parse_command_line(argv: List[str]) -> argparse.Namespace:  # noqa: C901.
     if not format_from_argv0:
         parser.add_argument(
             "--of",
-            "-of",
             "--output-format",
+            "-t",
+            "--to",
             dest="output_format",
             default="",
             help="output format",
             choices=FORMATS,
         )
+        parser.add_argument(
+            "-of",
+            dest="output_format",
+            default="",
+            help=argparse.SUPPRESS,
+            choices=FORMATS,
+        )
 
     parser.add_argument(
         "-p",

tests/test_remarshal.py

@@ -461,9 +461,9 @@ class TestRemarshal(unittest.TestCase):
     def test_run_no_input_file(self) -> None:
         argv = [
             sys.argv[0],
-            "-if",
+            "--from",
             "json",
-            "-of",
+            "--to",
             "json",
             "fake-input-file-that-almost-certainly-doesnt-exist-2382",
         ]