feat: add support for package self-referencing

[RebeccaStevens]

fix #87

[webpro]

TIL about self-referencing a package using its name :) Hats off for picking this up in this oddly organized codebase, including tests & fixtures! Also glad you worked against v2.

[RebeccaStevens]

The windows test seems to be failing due to upstream issue.
Where exactly that issue is, I'm not sure. It might be in node itself.

[webpro]

The windows test seems to be failing due to upstream issue. Where exactly that issue is, I'm sure. It might be in node itself.

Yes, facing this too:

  error: |-
    Cannot find module './build'
    Require stack:
    - C:/Users/larsk/Projects/knip/tests/fixtures/workspaces-self-reference/packages/eslint-config-self-reference
  code: 'MODULE_NOT_FOUND'
  stack: |-
    Module._resolveFilename (node:internal/modules/cjs/loader:995:15)
    u.default._resolveFilename (C:\Users\larsk\Projects\knip\node_modules\@esbuild-kit\cjs-loader\dist\index.js:1:1519)
    Function.resolve (node:internal/modules/cjs/helpers:109:19)
    <anonymous> (c:\Users\larsk\Projects\knip\src\index.ts:187:40)

[webpro]

I opened RebeccaStevens#1 to better describe what I meant and added some comments in the code as well. Did you see that? Perhaps a bit odd to open a PR this way, but alas :)

[webpro]

Alright, let's go! I'm very grateful for your efforts @RebeccaStevens