Restructure repo: single source file with git tags for versioning

Drop versioned directories and archive/ in favor of git tags (draft-00,
draft-01) for frozen submissions. Rename source to
draft-nennemann-wimse-ect.md (version comes from docname in front matter).
Update build.sh to extract docname automatically. Ignore generated outputs.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

build.sh

@@ -1,22 +1,39 @@
 #!/bin/bash
 set -e
 
-DRAFT="draft-nennemann-wimse-ect-01"
 DIR="$(cd "$(dirname "$0")" && pwd)"
+SRC="$DIR/draft-nennemann-wimse-ect.md"
+
+# Extract docname from YAML front matter
+DRAFT=$(grep '^docname:' "$SRC" | head -1 | awk '{print $2}')
+if [ -z "$DRAFT" ]; then
+  echo "Error: could not extract docname from $SRC"
+  exit 1
+fi
 
 # Tool paths
-KRAMDOWN="/usr/local/lib/ruby/gems/3.4.0/bin/kramdown-rfc2629"
-XML2RFC="/Users/christian/Library/Python/3.9/bin/xml2rfc"
+KRAMDOWN="$(which kramdown-rfc2629 2>/dev/null)"
+XML2RFC="$(which xml2rfc 2>/dev/null)"
+
+if [ -z "$KRAMDOWN" ]; then
+  echo "Error: kramdown-rfc2629 not found. Install with: gem install kramdown-rfc2629"
+  exit 1
+fi
+if [ -z "$XML2RFC" ]; then
+  echo "Error: xml2rfc not found. Install with: pip install xml2rfc"
+  exit 1
+fi
 
 export PYTHONWARNINGS="ignore::UserWarning"
 
+echo "Building: $DRAFT"
 echo "Using kramdown-rfc2629: $KRAMDOWN"
 echo "Using xml2rfc:          $XML2RFC"
 echo ""
 
 # Step 1: Markdown -> XML
 echo "Converting markdown to XML..."
-"$KRAMDOWN" "$DIR/$DRAFT.md" > "$DIR/$DRAFT.xml"
+"$KRAMDOWN" "$SRC" > "$DIR/$DRAFT.xml"
 
 # Step 2: XML -> TXT
 echo "Generating text output..."