minor #188 Improve CONTRIBUTING.md & Psalm config (jmsche)

This PR was squashed before being merged into the main branch.

Discussion
----------

Improve CONTRIBUTING.md & Psalm config

Commits
-------

e3ffc94 Improve CONTRIBUTING.md & Psalm config

.github/workflows/static.yml

@@ -74,7 +74,7 @@ jobs:
           composer-options: "--working-dir=tools/psalm"
 
       - name: Psalm
-        run: tools/psalm/vendor/bin/psalm --no-progress --php-version=8.0
+        run: tools/psalm/vendor/bin/psalm --no-progress
 
   composer-normalize:
     name: Composer Normalize

CONTRIBUTING.md

@@ -1,12 +1,12 @@
 Contributing
-------------
+============
 
 When contributing, you can fix some things that will be detected by CI anyway *before* sending your pull request.
 
 The following tools will be installed in the `tools` directory, so they don't share the bundle requirements.
 
 PHPStan
-=======
+-------
 
 ```bash
 composer install --working-dir=tools/phpstan
@@ -16,7 +16,7 @@ tools/phpstan/vendor/bin/phpstan analyze --generate-baseline
 ```
 
 PHP CS Fixer
-============
+------------
 
 ```bash
 composer install --working-dir=tools/php-cs-fixer
@@ -27,9 +27,16 @@ tools/php-cs-fixer/vendor/bin/php-cs-fixer fix --diff
 ```
 
 Psalm
-=====
+-----
 
 ```bash
 composer install --working-dir=tools/psalm
-tools/psalm/vendor/bin/psalm --php-version=8.0
+tools/psalm/vendor/bin/psalm
+```
+
+PHPUnit
+-------
+
+```bash
+./vendor/bin/simple-phpunit
 ```

psalm.xml

@@ -6,6 +6,7 @@
     xmlns="https://getpsalm.org/schema/config"
     xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd"
     errorBaseline="psalm.baseline.xml"
+    phpVersion="8.0"
 >
     <projectFiles>
         <directory name="src" />