Improve the .gitignore file (#959)

List the ignore patterns in groups referring to https://github.com/github/gitignore/blob/master/Python.gitignore.

Sort alphabetically in each group.

Some files have also been added:

- `.DS_Store` which is only for macOS
- `results/` which is generated when running pytest
- `.egg` which is generated when making distributions

Co-authored-by: Wei Ji <[email protected]>
Co-authored-by: Dongdong Tian <[email protected]>

Author: 3 people

.gitignore

@@ -1,26 +1,46 @@
-*.pyc
-*~
+# Byte-compiled / optimized / DLL files
+*.py[cd]
+
+# C extensions
 *.so
-*.pyd
-.*.swp
-*.egg-info
-.coverage
-.cache
-.env
+
+# Distribution / packaging
+build/
+dist/
+*.egg
+*.egg-info/
+.eggs/
 MANIFEST
+
+# Unit test / coverage reports
+.cache
+.coverage
+coverage.xml
+htmlcov/
 .pytest_cache/
-.ipynb_checkpoints/
-.vscode/
+results/
 result_images/
 tmp-test-dir-with-unique-name/
-coverage.xml
-htmlcov
-build/
-dist/
-doc/_build
-doc/modules
-doc/gallery
-doc/tutorials
-doc/projections
-doc/api/gmt*.rst
-doc/api/generated
+
+# Sphinx documentation
+doc/api/generated/
+doc/_build/
+doc/gallery/
+doc/projections/
+doc/tutorials/
+
+# Jupyter Notebook
+.ipynb_checkpoints/
+
+# Visual Studio Code
+.vscode/
+
+# Environments
+.env
+
+# Backup copies / swap files
+*~
+.*.swp
+
+# macOS
+.DS_Store