Rename attribute selection to attribute lookup

[roberth]

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

ExprSelect is a.b, and a.b or c (for metavariables a, b, c)

"Lookup" is less ambiguous than "select", and a more readily available term.

Describe the solution you'd like

• Change all occurrences of attribute selection to attribute lookup in the docs
• s/ExprSelect/ExprAttrLookup

Describe alternatives you've considered

"Get", which is ugly in natural language. How would you say "attribute lookup": "attribute getting"? You'd need more words to make it not suck.

Additional context

• Proxy like abstraction for an attrset #8187 (comment)

Priorities

Add 👍 to issues you find important.

[fricklerhandwerk]

Triaged in Nix team meeting 2023-05-12:

• @regnat: no strong opinion
• @eriscon2314: could delegate to the docs team
• @fricklerhandwerk will think about it, but low priority
  • may be something for @NixOS/documentation-team to discuss briefly
• @Ericson2314: should we rename attribute to field?
• @edolstra: should probably rename attribute set to dictionary, since it's not a set
  • but large scale renames are problematic because all the documentation will refer to the old name

[nixos-discourse]

This issue has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/2023-05-12-nix-team-meeting-minutes-54/28197/1