restrict actions trigger to source and add editorconfig

.editorconfig

@@ -0,0 +1,17 @@
+root = true
+
+[*]
+charset = utf-8
+
+[*.yml]
+end_of_line = lf
+insert_final_newline = true
+indent_size = 2
+indent_style = space
+
+[{*.c,*.cpp,*.h,*.hpp,*.cmake,CMakeLists.txt}]
+end_of_line = lf
+insert_final_newline = true
+indent_size = tab
+indent_style = tab
+tab_width = 4