chore: format comments and doc strings

wrap comments enables formatting of doc-strings.
we have to provide comment_width since it is different from max_width

Author: fewerner

.rustfmt.toml

@@ -1,6 +1,8 @@
 use_try_shorthand = true
 use_field_init_shorthand = true
 max_width = 120
+comment_width = 120
+wrap_comments = true
 newline_style = "Unix"
 merge_derives = true
 condense_wildcard_suffixes = true