Updated tutorial for Docker and Singularity for Linux

[rolivella]

The modified file is a tutorial on how to run FragPipe using Docker and Apptainer (formerly Singularity). It explains how to pull and run the fcyucn/fragpipe:<version> container in Docker, convert it into a Singularity image, and then run FragPipe using both containerization tools. The guide includes the necessary prerequisites for installing Docker and Apptainer on Linux, along with step-by-step instructions for running FragPipe in both environments, converting Docker images, and handling permissions with sudo.