docs: README: defer table of contents to GitHub UI

Author: joonas-fi

README.md

@@ -1,3 +1,5 @@
+⬆️ For table of contents, click the above icon
+
 ![Build status](https://github.com/function61/edgerouter/workflows/Build/badge.svg)
 [![Docker pulls](https://img.shields.io/docker/pulls/fn61/edgerouter.svg?style=for-the-badge)](https://hub.docker.com/r/fn61/edgerouter/)
 [![GoDoc](https://img.shields.io/badge/godoc-reference-5272B4.svg?style=for-the-badge)](https://pkg.go.dev/github.com/function61/edgerouter)
@@ -7,12 +9,6 @@ functions and S3 static websites.
 
 ![Architecture drawing](docs/architecture.png)
 
-Contents:
-
-- [Features](#features)
-- [Documentation](#documentation)
-- [Application configuration](#application-configuration)
-
 
 Features
 --------