docs: regenerate examples list and drop obsolete svn instructions

- EXAMPLES.md now lists all 54 apps; generated by
  scripts/generate_examples_doc.sh so it cannot drift again
- Replace dead 'svn checkout' instructions in GETTING_STARTED.md
  (GitHub removed SVN support) with git sparse-checkout

scripts/generate_examples_doc.sh

@@ -0,0 +1,92 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Regenerates documentation/EXAMPLES.md from the example app folders on disk.
+# Run via `make docs` after adding or removing an example app.
+
+source "$(dirname "${BASH_SOURCE[0]}")/common.sh"
+
+OUT="documentation/EXAMPLES.md"
+
+# Apps that demonstrate multiple features and are listed separately.
+COMPLETE_APPS=(
+	covid19_mobile_app
+	bmi_calculator
+	expense_planner
+	using_firebase_db
+	tip_calculator
+)
+
+# Folder -> display title overrides for non-obvious names.
+declare -A TITLES=(
+	[statless_counter_app]="Stateless Counter App"
+	[sliver_app_bar_example]="Sliver App Bar"
+	[using_listwheelscrollview]="Using ListWheelScrollView"
+)
+
+title_from_folder() {
+	local folder="$1"
+	if [ -n "${TITLES[$folder]:-}" ]; then
+		echo "${TITLES[$folder]}"
+		return
+	fi
+	local words
+	words=$(echo "$folder" | tr '_' ' ')
+	local out=""
+	for w in $words; do
+		case "$w" in
+			sqlite) w="SQLite" ;;
+			json) w="JSON" ;;
+			http) w="HTTP" ;;
+			pdf) w="PDF" ;;
+			qr) w="QR" ;;
+			getx) w="GetX" ;;
+		esac
+		out="$out ${w^}"
+	done
+	echo "${out# }"
+}
+
+is_complete_app() {
+	local folder="$1"
+	local candidate
+	for candidate in "${COMPLETE_APPS[@]}"; do
+		[ "$candidate" = "$folder" ] && return 0
+	done
+	return 1
+}
+
+apps=()
+for dir in ./*; do
+	if [ -f "$dir/pubspec.yaml" ]; then
+		apps+=("$(basename "$dir")")
+	fi
+done
+IFS=$'\n' apps=($(sort <<<"${apps[*]}")); unset IFS
+
+{
+	echo "# Example Apps"
+	echo ""
+	echo "Each folder in this repository is a standalone Flutter example app."
+	echo ""
+	echo "## Individual examples"
+	echo ""
+	local_apps=()
+	for app in "${apps[@]}"; do
+		if ! is_complete_app "$app"; then
+			local_apps+=("$app")
+		fi
+	done
+	for app in "${local_apps[@]}"; do
+		echo "1. [$(title_from_folder "$app")](/$app)"
+	done
+	echo ""
+	echo "## Complete apps with multiple features"
+	echo ""
+	for app in "${COMPLETE_APPS[@]}"; do
+		echo "1. [$(title_from_folder "$app")](/$app)"
+	done
+	echo ""
+} > "$OUT"
+
+echo "  Regenerated $OUT with ${#apps[@]} apps."