Add top-level .editorconfig; improve app/.editorconfig (#8178)

.editorconfig

@@ -0,0 +1,20 @@
+# https://editorconfig.org
+
+# Tip: to find files violating the rules set out here, run `docker run --rm --volume=$PWD:/check mstruebing/editorconfig-checker`
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 4
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.yaml]
+indent_size = 2
+
+
+[*.yml]
+indent_size = 2

app/.editorconfig

@@ -1,19 +1,12 @@
 # https://editorconfig.org
 
+# note: the files in ./composer actually use 4 spaces instead of tabs
+
 root = true
 
 [*]
 charset = utf-8
 end_of_line = lf
-indent_size = 4
 indent_style = tab
 insert_final_newline = true
 trim_trailing_whitespace = true
-
-[*.feature]
-indent_size = 2
-indent_style = space
-
-[*.yml]
-indent_size = 2
-indent_style = space