feat(cli): add render command as alias to manim render (#317)

* feat(cli): add render command as alias to `manim render`

* feat(cli): add render command as alias to `manim render`

* chore(test): add test

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* chore(lib): simplify how ManimGL rendering is called

* chore(lib): test

* chore(ci): try identify error

* wip

* chore(test): add result output

* try: checkout

* Revert "try: checkout"

This reverts commit 60985f0b61.

* fix(deps): don't update lock

* chore(lib): simplify code and improve usage

* chore(cli): better cli

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* fix: does this fix?

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

manim_slides/render.py

@@ -0,0 +1,54 @@
+"""
+Alias command to either
+``manim render [OPTIONS] [ARGS]...`` or
+``manimgl [OPTIONS] [ARGS]...``.
+
+This is especially useful for two reasons:
+
+1. You can are sure to execute the rendering command with the same Python environment
+   as for ``manim-slides``.
+2. You can pass options to the config.
+"""
+
+import subprocess
+import sys
+from typing import Tuple
+
+import click
+
+
+@click.command(
+    context_settings=dict(
+        ignore_unknown_options=True, allow_extra_args=True, help_option_names=("-h",)
+    ),
+    options_metavar="[-h] [--CE|--GL]",
+)
+@click.option(
+    "--CE",
+    is_flag=True,
+    envvar="MANIM_RENDERER",
+    show_envvar=True,
+    help="If set, use Manim Community Edition (CE) renderer. "
+    "If this or --GL is not set, default to CE renderer.",
+)
+@click.option(
+    "--GL",
+    is_flag=True,
+    envvar="MANIMGL_RENDERER",
+    show_envvar=True,
+    help="If set, use ManinGL renderer.",
+)
+@click.argument("args", metavar="[RENDERER_ARGS]...", nargs=-1, type=click.UNPROCESSED)
+def render(ce: bool, gl: bool, args: Tuple[str, ...]) -> None:
+    """
+    Render SCENE(s) from the input FILE, using the specified renderer.
+
+    Use 'manim-slides render --help' to see help information for
+    a the specified renderer.
+    """
+    if ce and gl:
+        raise click.UsageError("You cannot specify both --CE and --GL renderers.")
+    if gl:
+        subprocess.run([sys.executable, "-m", "manimlib", *args])
+    else:
+        subprocess.run([sys.executable, "-m", "manim", "render", *args])