docs migration - Configuring Emacs for Swift Development

[heckj]

Source: documentation/articles/zero-to-swift-emacs.md
Proposed disposition: Migrate
Proposed destination: ecosystem-tools/Sources/EcosystemTools.docc/zero-to-swift-emacs.md
Reviewer: @swiftlang/ecosystem-steering-group

Checklist

• Create a GitHub issue to track this migration
• Determine disposition (suggested: Migrate) and confirm destination
• Review source for accuracy against current Emacs packages and SourceKit-LSP integration
• Translate Jekyll markdown to DocC markdown format
  • Remove YAML front matter
  • Convert any Jekyll callouts to DocC-style callouts
  • Verify package installation steps (MELPA, swift-mode, lsp-mode) are current
  • Update any platform-specific version references
• Add article to EcosystemTools.docc/Documentation.md under an "Editor Configuration" topic group
• Run swift package generate-documentation --analyze --warnings-as-errors in ecosystem-tools/
• Preview locally with swift package --disable-sandbox preview-documentation in ecosystem-tools/
• Submit PR to this repository for ecosystem steering group review
• After merge and publication: add redirect_to: in the swift.org source file's front matter
• Submit redirect PR to swift-org-website