GWEB 0.1.5

GWEB 0.1.5 — error locations that point back to your .w source.

Highlights

• gtangle -line (the headline feature, on by default). The tangled Go now
  carries //line directives, so the Go compiler, go vet, and panic traces
  report errors at .w positions instead of .go ones — the Go counterpart
  of CWEB's #line. They survive gofmt (each rides with the code line it
  precedes). Pass -line=false to omit them; GWEB tangles its own sources that
  way, keeping the committed Go and the self-hosting fixpoint clean.

Also in this release

• Vim and Emacs syntax highlighting for .w files, alongside the existing
  VS Code extension (editors/vim, editors/emacs).
• Manual rewritten for readers who already know CWEB, typeset in the format
  of Knuth & Levy's cwebman.tex (doc/gwebman.tex, make manual).
• CI now lints Markdown (markdownlint), plus a project .markdownlint.jsonc.

The self-hosting fixpoint (lit/*.w reproduce the committed Go byte-for-byte),
go test, go vet, and gofmt are all green.