chore: import upstream snapshot with attribution

rustfmt.toml

@@ -0,0 +1,42 @@
+#  ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
+#  ┃ ██████ ██████ ██████       █      █      █      █      █ █▄  ▀███ █       ┃
+#  ┃ ▄▄▄▄▄█ █▄▄▄▄▄ ▄▄▄▄▄█  ▀▀▀▀▀█▀▀▀▀▀ █ ▀▀▀▀▀█ ████████▌▐███ ███▄  ▀█ █ ▀▀▀▀▀ ┃
+#  ┃ █▀▀▀▀▀ █▀▀▀▀▀ █▀██▀▀ ▄▄▄▄▄ █ ▄▄▄▄▄█ ▄▄▄▄▄█ ████████▌▐███ █████▄   █ ▄▄▄▄▄ ┃
+#  ┃ █      ██████ █  ▀█▄       █ ██████      █      ███▌▐███ ███████▄ █       ┃
+#  ┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┫
+#  ┃ Copyright (c) 2017, the Perspective Authors.                              ┃
+#  ┃ ╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌ ┃
+#  ┃ This file is part of the Perspective library, distributed under the terms ┃
+#  ┃ of the [Apache License 2.0](https://www.apache.org/licenses/LICENSE-2.0). ┃
+#  ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
+
+# * Always insert a newline after a dedent, unless the next line is also a
+#   dedent.
+# * Always insert a newline before a comment, unless the comment line is also
+#   an indent.
+# * Always insert a newline before and after top-level `use` declarations,
+#   which should be at the top of the file after the header.
+# * Prefer no newlines otherwise.
+#
+# [html!]
+# * Always remove spacing after `<`, before `>` and `/>`, and around `=`
+#   literals.
+# * Always insert spaces around content within `{}` blocks.
+
+unstable_features = true
+wrap_comments = true
+use_field_init_shorthand = true
+format_code_in_doc_comments = true
+format_macro_bodies = true
+format_macro_matchers = true
+format_strings = true
+overflow_delimited_expr = true
+normalize_comments = true
+normalize_doc_attributes = true
+reorder_impl_items = true
+group_imports = "StdExternalCrate"
+imports_granularity = "Module"
+newline_style = "Unix"
+condense_wildcard_suffixes = true
+match_block_trailing_comma = true
+yew.use_small_heuristics = "Max"