stack update

Author: pmbittner

INSTALL.md

@@ -14,11 +14,13 @@ After you installed stack, please open a terminal and navigate to the repository
 ```shell
 cd <path/to/this/repository>
 ```
+Before running the demo you should update stack as you might get errors otherwise:
+```shell
+stack update
+```
 Our demo prints coloured text to the terminal, so it might not be compatible with every terminal.
 We tested it within the Windows Terminal, Windows Powershell, Windows Subsystem for Linux (WSL), and the default terminal on Manjaro.
-(It might not work with Git Bash.)
 You can then build the library and run the demo as follows:
-
 ```shell
 stack run
 ```