#3 Implement ability to override the glyph used for dead/alive

[sinon]

Why?

Request from: #3

Allow configuring what character glyph is used for the dead/alive state

What?

Allow Grid to override what char is used to render each cell.
Update cargo config to not include ratatui/crossterm when not building the TUI binary

[codecov]

Codecov Report

Attention: Patch coverage is 98.71795% with 1 line in your changes missing coverage. Please review.

Project coverage is 85.6%. Comparing base (a9d7b15) to head (4ba28a9).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/lib.rs	98.6%	1 Missing ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
src/main.rs	71.4% <100.0%> (ø)
src/lib.rs	95.3% <98.6%> (+1.1%)	⬆️