documentation about entry points is unclear

[ChrisKeefe]

First, thanks for making an awesome tool! Click made knocking together a CLI for my masters work trivial.

These documentation questions are an effort to clarify some of the language in the setuptools and shell completion sections, to reduce friction for new users like me.

1. Though Shell Completion depends on users installing through a setuptools entrypoint, and refers to the Setuptools Integration docs, the terminology is not aligned between the two sets of examples. Scripts in Packages refers to the package yourpackage, a subpackage scripts, a module yourscript, and a click command cli. Shell Completion refers to PROG_NAME, "the executable name in uppercase...". Does PROG_NAME map to the the name of the package yourscript, the entrypoint yourscript, the command cli, or something else entirely? Clarification of exactly what the "executable name" is here would be very helpful.
2. In the Scripts in Packages example, it is unclear that the console_scripts key is a "default" value, and not something package-specific. For users who have worked with entrypoints in setup.py before, this is probably obvious, but for newcomers there's no visual way to differentiate "standard" values from semantically meaningful ones in this example. A single-sentence note clarifying would help.

• Python version: 3.8
• Click version: 8

[davidism]

Happy to review a PR.