Add a basic .editorconfig file

Signed-off-by: Lars Grefer <eclipse@larsgrefer.de>

.editorconfig

@@ -0,0 +1,20 @@
+# EditorConfig is awesome: https://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+end_of_line = lf
+insert_final_newline = true
+
+[*.yml]
+indent_style = space
+indent_size = 2
+
+[*.xml]
+trim_trailing_whitespace = true
+
+[*.{java,aj}]
+charset = utf-8
+trim_trailing_whitespace = true