feat: smarter initial mode prompt

[JoshuaKGoldberg]

PR Checklist

• Addresses an existing open issue: fixes 🚀 Feature: Enhance/streamline the CLI's startup (mode switching) #884
• That issue was marked as status: accepting prs
• Steps in CONTRIBUTING.md were taken

Overview

Enhances promptForMode to give different options based on the current directory:

• If it's empty, offer to create a new repository in it or a child directory
• If it's a Git directory, offer to initialize or migrate
• If it's not a Git directory, runs create for a new repository in a child directory

In doing so, adds an optional --directory that defaults to the repository's name.

Also cleans up getPrefillOrPromptedOption a bit. Instead of allowing an existingValue parameter, calls to getPrefillOrPromptedOption are just put in the right-hand-side of a ??.

[github-actions]

PR Compliance Checks Passed!

[codecov]

Codecov Report

Merging #919 (9e04a26) into main (dbf0ef9) will decrease coverage by 0.44%.
Report is 1 commits behind head on main.
The diff coverage is 80.39%.

@@            Coverage Diff             @@
##             main     #919      +/-   ##
==========================================
- Coverage   93.77%   93.33%   -0.44%     
==========================================
  Files          90       90              
  Lines        4800     4890      +90     
  Branches      394      402       +8     
==========================================
+ Hits         4501     4564      +63     
- Misses        298      325      +27     
  Partials        1        1              

Flag	Coverage Δ
create	71.85% <37.86%> (-0.75%)	⬇️
initialize	37.59% <30.17%> (-0.35%)	⬇️
migrate	70.69% <30.17%> (-0.74%)	⬇️
unit	68.11% <78.92%> (+0.24%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
src/bin/index.ts	100.00% <100.00%> (ø)
src/bin/promptForMode.ts	100.00% <100.00%> (ø)
src/create/createAndEnterGitDirectory.ts	100.00% <100.00%> (ø)
src/create/index.ts	95.58% <100.00%> (-0.07%)	⬇️
src/initialize/index.ts	97.72% <100.00%> (ø)
src/migrate/index.ts	97.72% <100.00%> (ø)
src/shared/options/args.ts	100.00% <100.00%> (ø)
src/shared/options/createOptionDefaults/index.ts	100.00% <100.00%> (ø)
...options/createOptionDefaults/parsePackageAuthor.ts	100.00% <ø> (ø)
...ons/createOptionDefaults/readDefaultsFromReadme.ts	100.00% <ø> (ø)
... and 4 more

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[github-actions]

🎉 This is included in version v1.32.0 🎉

The release is available on:

• GitHub releases
• npm package (@latest dist-tag)

Cheers! 📦🚀