Introduce .rustfmt.toml

[PoOnesNerfect]

Is your feature request related to a problem? Please describe.
Introduce .rustmft.toml file to standardize formatting within the project

Describe the solution you'd like
Here are the rules that I use for my projects over the years, for example.

unstable_features = true

max_width = 80
single_line_let_else_max_width = 60
single_line_if_else_max_width = 60

tab_spaces = 4
array_width = 60
struct_lit_width = 20
struct_variant_width = 20
indent_style = "Block"

condense_wildcard_suffixes = true
imports_granularity = "Crate"
fn_single_line = true
format_code_in_doc_comments = true
format_strings = true
group_imports = "StdExternalCrate"
overflow_delimited_expr = true
reorder_impl_items = true
wrap_comments = true

[BenJeau]

I'm good to standardize the formatting. I do not have any preference regarding this though.

Is it that the default configuration is too lenient and not strict enough?