Docs update: default is pip

[tmct]

No description provided.

[ofek]

It is accurate, can you please explain?

[tmct]

Hi, apologies for not leaving a comment before.

I came across this docs file, and it seemed to me that it may not be correct in its current state as uv is not enabled by default in hatch run? This is borne out in practice and in the other docs pages, e.g.:
https://hatch.pypa.io/dev/how-to/environment/select-installer/#enabling-uv

However, now I look more closely, it seems that this particular "internal" docs page is actually only talking about hatch build, which may have a different default installed to hatch run! Sorry, will have to check this is accurate - most likely the existing docs are correct.