chore(lib): reduce import overhead (#147)

* chore(lib): reduce import overhead

This PR should reduce the import time overhead caused by manim imports. To solve this, manim is only imported when Slide or ThreeDSlide is needed. A custom logger is now defined, which copies the one from Manim Community. FFMPEG_BIN is now hardcoded, but should be configurable in the future via the CLI or some config file.

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

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

* fix(lib): remove last .manim import

* fix(lib): remove print

* chore(lib): fix typo

---------

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

manim_slides/logger.py

@@ -0,0 +1,42 @@
+"""
+Logger utils, mostly copied from Manim Community:
+https://github.com/ManimCommunity/manim/blob/d5b65b844b8ce8ff5151a2f56f9dc98cebbc1db4/manim/_config/logger_utils.py#L29-L101
+"""
+
+import logging
+
+from rich.logging import RichHandler
+
+__all__ = ["logger", "make_logger"]
+
+HIGHLIGHTED_KEYWORDS = [  # these keywords are highlighted specially
+    "Played",
+    "animations",
+    "scene",
+    "Reading",
+    "Writing",
+    "script",
+    "arguments",
+    "Invalid",
+    "Aborting",
+    "module",
+    "File",
+    "Rendering",
+    "Rendered",
+]
+
+
+def make_logger() -> logging.Logger:
+    """
+    Make a logger similar to the one used by Manim.
+    """
+    RichHandler.KEYWORDS = HIGHLIGHTED_KEYWORDS
+    rich_handler = RichHandler(
+        show_time=True,
+    )
+    logger = logging.getLogger("manim-slides")
+    logger.addHandler(rich_handler)
+    return logger
+
+
+logger = logging.getLogger("manim-slides")