[Feature request] change `cargo about init` to generate the statement including user's project name.

[kyu08]

Thank you for always maintaining cargo-about! This tool makes license management for cargo project much easier.

If you agree with my proposal, I can submit a PR.

Is your feature request related to a problem? Please describe.

For now, the file generated by cargo about init includes the following lines.

        <div class="intro">
            <h1>Third Party Licenses</h1>
            <p>This page lists the licenses of the projects used in cargo-about.</p>
        </div>

Users should rename cargo-about to their own project name, because the above means a file generated by cargo about generate shows cargo-about's third party licenses. (Unfortunately, lots of users do not change this part.)

If cargo-about could do this automatically, it would be more user-friendly.

Describe the solution you'd like

I propose to change cargo about init to generate the statement including user's project name.

        <div class="intro">
            <h1>Third Party Licenses</h1>
            <p>This page lists the licenses of the projects used in your-project-name.</p>
        </div>

Describe alternatives you've considered

N/A

How to implement

1. Change cargo-about to {{project_name}} in This page lists the licenses of the projects used in cargo-about. in default.hbs.
2. Replace {{project_name}} with actual project name in init command.
   1. Retrive actual project name using krates::cm::MetadataCommand::new().exec()?.root_package()?.name; here.
   2. Replace {{project_name}} with the actual project name using Handlebars like this.

It might be too much to use Handlebars for this. If so, it might be better to use just str::replace or something instead of Handlebars.