Drupal 9 compatibility and some bug fixes

.editorconfig

@@ -0,0 +1,22 @@
+# This file is for unifying the coding style for different editors and IDEs
+# editorconfig.org
+
+# Drupal Coding Standards
+# https://www.drupal.org/docs/develop/standards/coding-standards
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+tab_width = 2
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.txt]
+trim_trailing_whitespace = false
+
+[*.{md,json,yml}]
+trim_trailing_whitespace = false