docs: migrate from m2r2 to myst-parser (#701)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Documentation Updates**
- Updated documentation generation tools to use `myst_parser`, enhancing
Markdown compatibility and features.
	- Improved documentation processing and rendering capabilities.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: njzjz

docs/conf.py

@@ -49,7 +49,7 @@
     "sphinx.ext.viewcode",
     "sphinx.ext.intersphinx",
     "numpydoc",
-    "m2r2",
+    "myst_parser",
     "sphinxarg.ext",
     "jupyterlite_sphinx",
 ]

pyproject.toml

@@ -57,7 +57,7 @@ docs = [
     'recommonmark',
     'sphinx_rtd_theme>=1.0.0rc1',
     'numpydoc',
-    'm2r2',
+    'myst-parser',
     'deepmodeling-sphinx>=0.1.1',
     'sphinx-argparse<0.5.0',
     'rdkit',