DEV: add .editorconfig (scipy#22818)

Author: NeilGirdhar

.editorconfig

@@ -0,0 +1,29 @@
+root = true
+
+[*.{c,cxx,h,hpp}]
+# https://numpy.org/neps/nep-0045-c_style_guide.html
+indent_size = 4
+indent_style = space
+max_line_length = 88
+trim_trailing_whitespace = true
+
+[*.{md,py,pyi,pxd}]
+# https://peps.python.org/pep-0008/
+charset = utf-8
+end_of_line = lf
+indent_size = 4
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.py]
+# Keep in sync with `tools/lint.toml`
+# https://docs.astral.sh/ruff/settings/#line-length
+max_line_length = 88
+
+[*.pyi]
+# https://typing.readthedocs.io/en/latest/guides/writing_stubs.html#style-guide
+max_line_length = 130
+
+[*.md]
+max_line_length = 80