docs(readme): updated the description texts

README.md

@@ -4,11 +4,17 @@
 
 ## Background
 
-If you work with different docker environments at the same time you need to manage the ports. *wp-env* uses port 8888 by default. If this port is already in use by another project then you have a problem. But the solution is easy: Just change the ports. 
+If you are working with different Docker environments at the same time, you need to manage the ports. *wp-env* uses port 8888 by default. If this port is already used by another project, you have a problem. But the solution is simple: just change the ports.
 
-*wp-env-port-stamp* generates every time a new port address - more or less - randomly. When the package is called, it creates a file *.wp-env.json* in the directory where it was called. With this *.wp-env.json* file you can customize the WordPress installation. In our case dynamic rendered port numbers.
+*wp-env-port-stamp* generates a new port address - more or less - randomly. When the package is called, the following happens:
 
-The port number will be generated from the current JavaScript date - the time in milliseconds since the ECMAScript epoch. We take the last 4 numbers of this time as the port number. This solution my not be perfekt but good enough for your daily local web development with a handful docker instances. :-)
+* It checks if a file *.wp-env.json* exists in the executing directory.
+* If so, only the two ports are set or changed. The other values remain untouched.
+* If no, a new file is created.
+
+The port number is generated from the current JavaScript date - the time in milliseconds since the ECMAScript epoch. We take the last digits of this time as the port number. This number is somewhere between 1 and 65535. There is also a filter that prevents commonly used port numbers (e.g. 8888) from being used.
+
+My solution may not be perfect, but it is good enough for daily local web development with a handful of Docker instances :-)
 
 ## Install/Remove
 
@@ -31,5 +37,3 @@ npm uninstall -g wp-env-port-stamp
 3. The file is generated. You can start now with `wp-env`
 
 Normally you only need to call the package for the first time in a new project. Later just start directly *wp-env*.
-
-**Attention:** If there is already existing *.wp-env.json* file, *wp-env-port-stamp* will overwrite it! (There will be an improvement for this later.)