fix readme path

docs/SUMMARY.md

@@ -1,6 +1,6 @@
 # Table of contents
 
-* [Introduction](/README.md)
+* [Introduction](./README.md)
 * [Setup and Maintenance](./SetupMaintenance.md)
 * [Upgrading from Misago 0.5](./UpgradingFrom05.md)
 * [References](./ref/README.md)