code-style: add .editorconfig and update .gitignore

.editorconfig

@@ -0,0 +1,19 @@
+# EditorConfig helps developers define and maintain consistent
+# coding styles between different editors and IDEs
+# editorconfig.org
+
+root = true
+
+[*]
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+indent_style = space
+indent_size = 4
+
+[*.css]
+indent_size = 2
+
+[*.md]
+trim_trailing_whitespace = false

.gitignore

@@ -1,3 +1,4 @@
+venv/
 _build/
 __pycache__/
 *.py[cod]