qa: fix linting errors in documentation

Signed-off-by: Matthew Weier O'Phinney <matthew@weierophinney.net>

Author: weierophinney

README.md

@@ -1,7 +1,6 @@
 # laminas-progressbar
 
-[![Build Status](https://travis-ci.com/laminas/laminas-progressbar.svg?branch=master)](https://travis-ci.com/laminas/laminas-progressbar)
-[![Coverage Status](https://coveralls.io/repos/github/laminas/laminas-progressbar/badge.svg?branch=master)](https://coveralls.io/github/laminas/laminas-progressbar?branch=master)
+[![Build Status](https://github.com/laminas/laminas-progressbar/workflows/Continuous%20Integration/badge.svg)](https://github.com/laminas/laminas-progressbar/actions?query=workflow%3A"Continuous+Integration")
 
 laminas-progressbar is a component to create and update progress bars in different
 environments. It consists of a single backend, which outputs the progress through
@@ -23,6 +22,6 @@ Browse the documentation online at https://docs.laminas.dev/laminas-progressbar/
 
 ## Support
 
-* [Issues](https://github.com/laminas/laminas-progressbar/issues/)
-* [Chat](https://laminas.dev/chat/)
-* [Forum](https://discourse.laminas.dev/)
+- [Issues](https://github.com/laminas/laminas-progressbar/issues/)
+- [Chat](https://laminas.dev/chat/)
+- [Forum](https://discourse.laminas.dev/)

docs/book/index.md

@@ -0,0 +1 @@
+../../README.md

docs/book/index.md

@@ -6,8 +6,7 @@ through one of the multiple adapters. On every update, it takes an absolute
 value and optionally a status message, and then calls the adapter with some
 precalculated values like percentage and estimated time left.
 
-Basic Usage
------------
+## Basic Usage
 
 To use the component, instantiate `Laminas\ProgressBar\ProgressBar`, providing both
 a a min- and a max-value, and an adapter for providing data output. If you want
@@ -36,8 +35,7 @@ You can also call the `update()` method of `ProgressBar` without arguments;
 doing so recalculates ETA and notifies the adapter. This is useful when there is
 no data update but you want the progressbar to be updated.
 
-Persistent Progress
--------------------
+## Persistent Progress
 
 If you want the progressbar to be persistent over multiple requests, you can
 give the name of a session namespace as fourth argument to the constructor. In