Create documentation on how to run the library's tests

Author: DanielRamirez404

tests/README.md

@@ -0,0 +1,13 @@
+# How to run the tests
+
+> [!NOTE]
+> Requirements: ```Cmake```, ```Make``` and a ```C++``` compiler previously installed.  
+
+You have to create a ```build``` subdirectory inside of this one, and once you go there, run the commands: ```cmake ..``` and ```make``` on your shell, in that very order. This will create an executable that you'll be able to run.
+
+> [!TIP]
+> You can also chain the commands (including the creation of the build subdirectory) in order to create the executable file as follows:
+>   ```
+>   mkdir build && cd build && cmake .. && make
+>   ```
+> This should work at least on both ```Linux```'s terminal and ```Windows```'s ```CMD```.