Add 'Install and Usage'

Install-and-Usage.md

@@ -0,0 +1,22 @@
+## Executable file (.exe)
+
+- Just [download](https://git.pyas.de/Kim/prnt.sc_url_generator/raw/branch/master/prnt.sc_link_generator.exe) the
+  prepared/standalone file and you are done.
+- For downloads see also the [release page](https://git.pyas.de/Kim/prnt.sc_url_generator/releases).
+
+## Python script
+
+### Requirements
+
+- Python 3 required
+- No additional modules required, only built-ins are used.
+
+### Usage
+
+1. Set the 3 variables in the script to your desired state:
+    - `NUMBER_OF_LINKS_TO_GENERATE`: Generates X urls at a time
+    - `URL_AUTO_OPEN`: If set to *True* the script opens the URLs automatically in your browser
+    - `CLOSE_WINDOW_AFTER`: If set to True the Python window (if run in an desktop environment) won't close after the
+      script ends (keeps open to see/copy the original URL)
+2. Run the script
+3. Have fun searching through random screenshots