Enable some other experimental Ktlint rules

Those don't generate warnings, thus verify the current code style, and make sense in general

.editorconfig

@@ -56,7 +56,11 @@ ktlint_standard_wrapping = disabled
 
 # enable some experimental Ktlint rules
 ktlint_standard_function-expression-body = enabled
+ktlint_standard_function-type-modifier-spacing = enabled
+ktlint_standard_mixed-condition-operators = enabled
+ktlint_standard_kdoc = enabled
 ktlint_standard_multiline-loop = enabled
+ktlint_standard_square-brackets-spacing = enabled
 
 [gradlew]
 indent_style = space