chore: merge branch 'docs' into 'main'

docs:  Fill readme, remove unmantained status

See merge request perun-proxy-aai/simplesamlphp/simplesamlphp-module-attribute_check!9

README.md

 # simplesamlphp-module-attribute_check
 
-![maintenance status: unmaintained](https://img.shields.io/maintenance/end%20of%20life/2022)
+SimpleSAMLphp module for deploying an SP serving as an attribute check.
 
-This project is not maintained anymore, which means it does not receive any Security patches or bug fixes. Check out [SATOSA](https://github.com/IdentityPython/SATOSA) and various microservices instead.
+## Configuration
+
+See `config-templates` directory on how to configure the module.
+
+## Contribution
+
+This repository uses [Conventional Commits](https://www.npmjs.com/package/@commitlint/config-conventional).
+
+Any change that significantly changes behavior in a backward-incompatible way or requires a configuration change must be marked as BREAKING CHANGE.
+
+## Instalation
+
+`php composer.phar require cesnet/simplesamlphp-module-attribute_check`