[DOCS] Change text in docs for phive

Fixes: #543, #429

Documentation/DependencyManager.rst

@@ -6,11 +6,12 @@
 Dependency manager
 ==================
 
-To keep things simple, most development tools, for example PHP_CodeSniffer, are
-installed by Composer as development requirements and in some cases where
-installation via Composer is not possible, we use `PHIVE <https://phar.io/>`__.
+To keep things simple, we try do model as many dependencies as possible as
+Composer dependencies in the composer.json`. However, sometime a dependency
+is not available for all PHP versions that we support, or it might conflict
+with another dependency.
 
-PHIVE packages each tool with all its dependencies as
+`PHIVE <https://phar.io/>`__ manage each tool with all its dependencies as
 a separate PHAR. This helps avoid dependency hell (which means that you cannot
 install or upgrade some tool as the tool's dependencies conflict with the
 dependencies on another library). It also allows running versions of tools
@@ -22,12 +23,15 @@ for this project.
 Using PHIVE to install `phpunit/phpcov`
 =======================================
 
-To support php version 7.4 and 8.2 in the `tea` extension, we are using PHIVE
-to install `phpunit/phpcov`.
-We need `phpunit/phpcov` in version 10 to support php 8.2.
-Our minimum php version 7.4 would prevent the installation with composer.
+One of this cases is PHPCOV, a library we use to
+collect and transmit code coverage information: The version that works with
+PHP 8.2 and 8.3 does not work with PHP 7.3. So we have to switch this particular
+dependency from being installed via Composer to being installed via
+PHIVE.
+With the usage of PHIVE we can support a wider range of PHP versions in the tea
+extension.
 
 .. note::
 
    To find more information about install and usage,
-   please check out the documentation of `PHIVE <https://phar.io>`__.
+   please check out the documentation of `PHIVE <https://phar.io#Usage>`__.