Update and correct tests/README.md

Noted that all snippets in Arrays category now have unit tests.

Added warning that newer tests are only checked for compiling with
Delphi XE and later.

Corrected some errors and inconsistencies.

Author: delphidabbler

tests/README.md

@@ -2,6 +2,8 @@
 
 This project provides tests and demos of snippets from the [DelphiDabbler Code Snippets Database](https://github.com/delphidabbler/code-snippets).
 
+> ⚠️ Recent changes have only been compiled and tested with Delphi XE and later. While project files for earlier versions of Delphi remain available it is not guaranteed that any of the projects will compile with versions of Delphi prior to Delphi XE. 
+
 ## Directory Structure
 
 The project has the following directories:
@@ -15,7 +17,7 @@ Contains:
 
 ### `./Cat-Arrays`
 
-Contains the _TestArraysCat_[^2] project that provides _DUnit_ tests for snippets from the database's _Arrays_ category. Currently tests are only available for the _TArrayUtils_ advanced record.
+Contains the _TestArraysCat_[^2] project that provides _DUnit_ tests for all the snippets in the database's _Arrays_ category.
 
 ### `./Cat-Date`
 
@@ -27,19 +29,19 @@ Contains the _TestDriveCat_[^2] project that implements a GUI application that e
 
 ### `./Cat-Hex`
 
-Contains the _TestHexCat_[^2] project that provides _DUnit_ tests for all the snippets from the database's _Hex Utilities_ category.
+Contains the _TestHexCat_[^2] project that provides _DUnit_ tests for all the snippets in the database's _Hex Utilities_ category.
 
 ### `./Cat-Maths`
 
 Contains the _TestCatMaths_[^2] project that provides _DUnit_ tests for selected snippets from the database's _Mathematics_ category.
 
 ### `./Cat-String`
 
-Contains the _TestCatStructsXE_[^3] project that provides _DUnit_ tests for selected snippets from the database's _Structures_ category.
+Contains the _TestCatString_[^2] project that provides _DUnit_ tests for selected snippets from the database's _String Management_ category.
 
 ### `./Cat-Structs`
 
-Contains the _TestCatString_[^2] project that provides _DUnit_ tests for selected snippets from the database's _String Management_ category.
+Contains the _TestCatStructsXE_[^3] project that provides _DUnit_ tests for all snippets in the database's _Structures_ category.
 
 ### `./Cat-WinSys`