Merge pull request #1628 from edwinhuish/add_editorconfig

dcat 项目文件既有 lf，也有 crlf，添加 editorconfig 加以约束

.editorconfig

@@ -0,0 +1,18 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+indent_style = space
+indent_size = 4
+trim_trailing_whitespace = true
+
+[*.md]
+trim_trailing_whitespace = false
+
+[*.{yml,yaml}]
+indent_size = 2
+
+[docker-compose.yml]
+indent_size = 4