docs: restructure README to standard module documentation

Reorganized to follow the project's module documentation structure:
Abstract paragraph, Badges as bold key:value list, Topology section
with auto-generated mermaid graph, Controls describing player input,
Demonstrates listing the Sporel features showcased, References at
the end.

Install pre-commit hook via Sporel --install-hooks=.; topology is
auto-managed by Sporel --lint --fix.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.githooks/pre-commit

@@ -0,0 +1,13 @@
+#!/bin/sh
+# Sporel API-Doc-Convention pre-commit hook.
+SPOREL_EXE="${SPOREL_EXE:-$(command -v Sporel.exe 2>/dev/null || command -v sporel 2>/dev/null)}"
+if [ -z "$SPOREL_EXE" ]; then
+  echo "INFO: Sporel.exe not on PATH. Skipping lint." >&2
+  exit 0
+fi
+"$SPOREL_EXE" --lint="$(pwd)" --fix
+RC=$?
+if git diff --cached --name-only | grep -qx 'README.md'; then
+  git add README.md
+fi
+exit $RC