panic in Buffer::store

[leontoeides]

Thank you for the great crate!

I have a panic originating from the eddie crate.

There's a get_unchecked_mut that's marked as unsafe in buffer.rs on line 26 causing a panic.

stack backtrace:
   0: std::panicking::begin_panic_handler
             at /rustc/47ecded3525392b77843534bed69b4302f9af8d2/library\std\src\panicking.rs:646
   1: core::panicking::panic_nounwind_fmt::runtime
             at /rustc/47ecded3525392b77843534bed69b4302f9af8d2/library\core\src\panicking.rs:110
   2: core::panicking::panic_nounwind_fmt
             at /rustc/47ecded3525392b77843534bed69b4302f9af8d2/library\core\src\panicking.rs:120
   3: core::panicking::panic_nounwind
             at /rustc/47ecded3525392b77843534bed69b4302f9af8d2/library\core\src\panicking.rs:152
   4: core::slice::index::impl$2::get_unchecked_mut::precondition_check
             at /rustc/47ecded3525392b77843534bed69b4302f9af8d2\library\core\src\ub_checks.rs:66
   5: core::slice::index::impl$2::get_unchecked_mut<char>
             at /rustc/47ecded3525392b77843534bed69b4302f9af8d2\library\core\src\slice\index.rs:236
   6: core::slice::impl$0::get_unchecked_mut<char,usize>
             at /rustc/47ecded3525392b77843534bed69b4302f9af8d2\library\core\src\slice\mod.rs:728
   7: eddie::utils::buffer::Buffer<char>::store<char,core::str::iter::Chars>
             at C:\Users\Dylan\.cargo\registry\src\index.crates.io-6f17d22bba15001f\eddie-0.4.2\src\utils\buffer.rs:26
   8: eddie::str::leven::Levenshtein::similarity
             at C:\Users\Dylan\.cargo\registry\src\index.crates.io-6f17d22bba15001f\eddie-0.4.2\src\str\leven.rs:118
   9: indicium::simple::internal::eddie::autocomplete::context_levenshtein::impl$0::eddie_autocomplete_context_levenshtein::closure$2<usize>
             at .\src\simple\internal\eddie\autocomplete\context_levenshtein.rs:70