Add '.editorconfig'

Add [.editorconfig](http://editorconfig.org/) global settings (supported by gogs) to normalize code contributions. The default settings are what I use in my repos.
Must be reviewed by @Uncled1023 with attention to the following:

```
end_of_line = lf # or crlf for windows env?
trim_trailing_whitespace = true # or false, since it's not good for Markdown files?
```

.editorconfig

@@ -0,0 +1,9 @@
+root = true
+
+[*]
+charset = utf-8
+indent_style = space
+indent_size = 4
+end_of_line = lf
+trim_trailing_whitespace = true
+insert_final_newline = true