Add .editorconfig file (#221)

Trying this out. I like the idea of an editor agnostic, general config
file.

Author: Preocts

.editorconfig

@@ -0,0 +1,23 @@
+# This file is for unifying the coding style for different editors and IDEs.
+# It is not reqired for a project, but can be very helpful.
+# More information at http://EditorConfig.org
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+
+[*.py]
+indent_size = 4
+indent_style = space
+trim_trailing_whitespace = true
+max_line_length = 100
+
+[*.md]
+max_line_length = 79
+trim_trailing_whitespace = true
+
+[*.rst]
+max_line_length = 79