Adds a flake.nix so that Nix users can easily build and test the crate, as well as use it to retrieve the binary for NixOS users.

The patch also provides some fixes so that nix flake check succeeds.

git range-diff main 080eccb 2a078e0

1:  644e23e = 1:  644e23e ui: add missing doc
2:  2cb9fac = 2:  2cb9fac bin: use Display over ToString
3:  080eccb ! 3:  2a078e0 nix: add flake.nix
    @@ flake.lock (new)
      ## flake.nix (new) ##
     @@
     +{
    -+  description = "Build a cargo project";
    ++  description = "Radicle terminal user interface";
     +
     +  inputs = {
     +    nixpkgs.url = "github:NixOS/nixpkgs/release-24.05";
    @@ flake.nix (new)
     +        };
     +
     +        devShells.default = craneLib.devShell {
    -+          packages = [
    -+            pkgs.cargo-watch
    -+            pkgs.cargo-nextest
    -+            pkgs.ripgrep
    -+            pkgs.rust-analyzer
    ++          packages = with pkgs; [
    ++            cargo-watch
    ++            cargo-nextest
    ++            ripgrep
    ++            rust-analyzer
     +          ];
     +        };
     +      });

Changes:

• Fix to adding apps entry in flake.nix
• Add README entry for Nix
• Add CHANGELOG entries

Changes:

• Reword commit titles
• Reword CHANGELOG entries

fix(warning): input ‘rust-overlay’ has an override for a non-existent input ‘flake-utils’

fix(error): missing package definition

The error could be reproduced by runnin nix run.

error:
       … while evaluating the attribute 'packages.x86_64-linux.radicle-tui'
         at /nix/store/na7sykizsgkzh9i3wc8m8pz5xfqib2rv-source/lib.nix:40:24:
           39|                 ${key} = (attrs.${key} or { })
           40|                   // { ${system} = ret.${key}; };
             |                        ^
           41|               }

       error: attribute 'radicle-tui' missing
       at /nix/store/hqqa3dsg0gg91kmlkbqcylqbr92vj90n-source/flake.nix:116:17:
          115|           name = "rad-tui";
          116|           drv = self.packages.${system}.radicle-tui;
             |                 ^
          117|         };

chore(gitignore): add result to ignore nix build artifacts

Changes:

• Rebased and squashed commits
• Re-order of mod log line for alphabetical ordering – caught by cargo fmt

Rebased.

Bump Rust toolchain to current stable and update flake inputs.

Rebase to get rid of fixup commit.

Rebase

Fix CI fail with toolchain override