README.md: be more specific withDefaults application order

[spinus]

Contribution checklist (recommended but not always applicable/required):

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• Commit messages or code include references to related issues or PRs (including third parties)
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[spinus]

In relation to #1519

[Nebucatnetzer]

In general it looks good, some minor things and a few typos.

[Nebucatnetzer]

"it applies user overrides first and then applies defaults"

[Nebucatnetzer]

Please remember that the withDefaults function

Missing the

and then

Then instead of than.

If you want to change a package

Missing a.

[Nebucatnetzer]

Can you rewrite it like this?
The text and the code are separated by an empty line.

you can use the a snippet like the following which then puts your changes on top of the defaults:

```nix

[Nebucatnetzer]

@elikoga Can you explain to me the difference between the code snippet in this merge request and the way it is done here? jwpconsulting/projectify@5aef755

[elikoga]

@elikoga Can you explain to me the difference between the code snippet in this merge request and the way it is done here? jwpconsulting/projectify@5aef755

I believe it's just like justuswilhelm said in #1519 :

My overrides are created with

    overrides = defaultPoetryOverrides.extend (self: super: {

based off the poetry2nix flake guide, and just like @sigprof here recommended as well -- so perhaps that made a difference?

where extend is defined by https://noogle.dev/f/lib/makeExtensible

Compared to overrides.withDefaults, which is simply defined in poetry2nix and whose behaviour was changed in f36ad45