12: Compose some initial documentation

Task-Url: #12

README.md

@@ -6,10 +6,14 @@ The library is a wrapper around [Spring Security](https://spring.io/projects/spr
 
 While still being used, the former v1.4 is discontinued and - being based on OpenSAML 2 ([also discontinued](https://wiki.shibboleth.net/confluence/display/OpenSAML/Home)) - should be replaced with a recent version.
 
-## 1. Getting started
+## 1. Quickstart
+
+For a reference implementation and configuration of the security concepts, please see the [dariahsp-sample-boot](dariahsp-sample-boot) application.
+
+## 2. Getting started
 The library and sample application are deployed to the Maven repository available at https://minfba.de.dariah.eu/nexus. Repository configuration can be included in Maven and Gradle settings and build configurations with the following snippets.
 
-### 1.1 Maven setup
+### 2.1 Maven setup
 
 Please find information on the current version of dariahsp-core at the [respective package](https://minfba.de.dariah.eu/nexus/#browse/browse:minfba-central:eu%2Fdariah%2Fde%2Fdariahsp-core) in the deployment repository:
 
@@ -52,7 +56,7 @@ Include the dependency to dariahsp-core in your `pom.xml`.
 </dependency>
 ```
 
-### 1.2 Gradle setup
+### 2.2 Gradle setup
 
 #### Repository configuration
 
@@ -89,12 +93,10 @@ Include the dependency to dariahsp-core in your `build.gradle`.
 implementation 'eu.dariah.de:dariahsp-core:2.0.0-SNAPSHOT'
 ```
 
-## 2. Security concepts and entry points
+## 3. Security concepts and entry points
 
 As this library is based on Spring Security, concepts such as _Java-based configuration_, _filters_, _interceptors_ or _global method security_ can be referenced in the respective Spring documentation, e.g. [here](https://docs.spring.io/spring-framework/docs/current/reference/html/core.html) or [here](https://docs.spring.io/spring-framework/docs/current/reference/html/web.html) or [here](https://spring.io/guides/topicals/spring-security-architecture).
 
-For a reference implementation of the security concepts, please see the [dariahsp-sample-boot](dariahsp-sample-boot) application.
-
 Components that _only need import and activation_ in the target application:
 
 * `SecurityConfig`: Main configuration contains all security-related beans and can be imported into the applications configuration
@@ -107,7 +109,7 @@ One component requires _adaption_ in implementing applications:
 
 * `SecurityConfigurerAdapter` is intended to be extended by a concrete adapter that defines protected paths of the application.
 
-## 3. Configuration
+## 4. Configuration