Add configuration option for source location

[xortive]

This is a blocker for implementing live reloading that doesn't require user configuration. With wrangler supporting multi language builds, doing a webpack style traversal from the entry point is needlessly complex, when moving all source files into one directory and watching that recursively is a much easier problem.

we could use src or worker as a default (probably combine this with #206). As long as all of your source files are in this , the rest of your directory tree is irrelevant as we will recursively check the source directory for changes.

[xtuc]

I don't like your proposal because I don't want to assume the user's source directory. We should check how webpack does it exactly.

Related to #235.

Also worker is not a source directory currently; #206.

[xortive]

Webpack traverses imports/requires (looking in whatever you have set your resolve locations to) starting from the entry point, and also has an option to set paths/files to ignore.

I don't think reimplementing this is something we should do, but we could potentially change wranglerjs to not do dist-to-clean cleanup on livereloads and run webpack in watch mode and monitor the output of it. However, with projects that use webpack as well as rust/wasm this means they would have two places to configure hot reloading (webpack config, and wrangler.toml)

Cargo by default puts all source in <project-root>/src but this can be configured.

Ideally the solution we adopt supports all current project types, as well as any custom things in the future. I'm thinking we allow a config option that lets you specify file paths as well as source directories which will be searched recursively, and an ignore option that functions just like .gitignore rules do (we could even add an option to look at gitignore, reusing the ignore crate that ripgrep created)